WOOD 
PATTERN-MAKING 

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PURFIELD 


A    TRIMMER 


WOOD 
PATTERN -MAKING 

A  TEXTBOOK 

FOR    THE    USE    OF    HIGH    SCHOOL,  TRADE   SCHOOL, 

TECHNICAL  SCHOOL  AND  COLLEGE 
STUDENTS 


HORACE  TRAITON  PURFIELD 

or  in  Pattern-making  and  Foundry  Work,  High  School,  Fort  Wayne,  Ind. 
Formerly  Instructor  in  the  Shops  of  the  Engineering  Department 
of  the  University  of  Michigan 

With  drawings  by 

EDWIN  VICTOR  LAWRENCE 


SECOND  EDITION 


THE  MANUAL  ARTS  PRESS 

PEORIA.  ILLINOIS 


COPYRIGHT,  1906 
HORACE  TRAITON  PURFIELD 

COPYRIGHT,  1911 
HORACE  TRAITON  PURFIELD 


PREFACE  TO  FIRST  EDITION 

An  experience  of  seventeen  years  in  teaching  pat- 
tern-making and  kindred  subjects  has  made  me  feel 
the  great  need  of  such  a  work  as  this  which  I  now  offer 
as  a  textbook  for  students  in  technical  and  manual 
training  schools,  and  universities.  A  number  of  excel- 
lent books  on  the  subject  have  been  published,  to  be 
sure,  but  most  of  them  assume  on  their  reader's  part 
previous  acquaintance  with  the  fundamental  ideas  of 
pattern-making;  such  as  do  treat  at  all  of  the  element- 
ary part  of  the  subject,  happen  to  be  works  of  an 
exhaustive  character,  which  are  consequently  too  ex- 
pensive for  use  as  textbooks.  The  present  work, 
therefore,  will,  it  is  hoped,  find  a  field  of  usefulness 
for  itself. 

It  is  of  course  to  be  recognized  that  as  pattern- 
making  is  an  art,  it  cannot  be  learned  simply  by  reading 
any  book  on  the  subject,  but  only  by  practice.  Still 
a  textbook  may  afford  valuable  assistance  even  to  the 
artisan.  This  work,  however,  has  a  further  and  more 
important  purpose, — that  of  imparting  to  the  engineer 
or  the  draftsman  the  fundamental  principles  of  pattern- 
making.  For  only  as  he  is  in  possession  of  these  can 
he  make  designs  for  patterns  in  accordance  with  which 
shopwork  can  be  performed  in  the  most  efficient  and 
most  economical  manner.  The  reader  should  also 
understand  that  this  work,  being  designed  only  as  an 
elementary  treatise,  in  no  way  exhausts  the  subject. 


2065869 


4  PREFACE 

It  is  claimed,  however,  that  the  examples  of  pattern- 
making  submitted  indicate,  on  the  whole,  the  best 
methods  of  construction  and  those  most  easily  under- 
stood by  the  student. 

In  preparing  the  body  of  this  work,  I  have  received 
many  valuable  suggestions  which  have  been  incor- 
porated herewith,  and  which  will  have  contributed  to 
any  success  the  book  may  attain.  The  works  of  many 
previous  writers  on  the  subject  have  been  consulted 
also ;  for  specific  ideas  derived  from  them  credit  should 
be  given  to  Joshua  Rose,  M.  E.,  J.  Me  Kim  Chase,  and 
P.  S.  Dingey.  In  preparing  the  appendix  considerable 
help  was  afforded  me  by  the  little  book  of  W.  F.  M. 
Goss,  on  "Bench  Work  in  Wood."  With  these  few 
words  of  introduction,  I  leave  the  book  to  its  readers 
with  the  hope  that  it  will  assist  them  to  master  the 
important  subject  of  which  it  treats. 

H.  T.  P. 


PREFACE  TO  SECOND  EDITION 

In  presenting  the  second  edition  of  Wood  Pattern- 
Making,  I  wish  to  express  my  appreciation  of  the 
hearty  reception  given  to  the  first  edition,  and  at  the 
same  time  to  bespeak  as  kindly  treatment  of  the  pres- 
ent effort. 

The  book  has  been  thoroly  revised  and  several 
additions  made  to  it.  The  drawings  for  the  illustra- 
tions have  all  been  re-made  by  Edwin  V.  Lawrence, 
and  the  arrangement  of  the  subject  matter  has  been 
changed  so  that  the  chapters  on  tools  and  their  use 
now  appear  at  the  beginning  instead  of  the  end  of  the 
book.  It  is  hoped  that  this  change  will  add  to  the  use- 
fulness of  the  book,  especially  for  schools  giving  a 
short  course  in  general  woodworking  just  previous 
to  taking  up  pattern-making. 

Fort  Wayne,  Ind. 

April,  1911.  HORACE  T.  PURFIELD 


CONTENTS 

CHAPTER  L— HAND  TOOLS  FOR  WOOD 9 

Measuring  and  Lining  Appliances 11 

Chisels  and  Chisel-like  Tools  19 

Saws   22 

Boring  Tools  27 

Miscellaneous  Tools    30 

Planes  and  Plane-like  Tools   33 

Cutting  Wedges   41 

Laying  Out  Work   45 

CHAPTER  II.— LUMBER    46 

CHAPTER  III. — READING   WORKING   DRAWINGS 53 

CHAPTER  IV.— PATTERN    TURNING 60 

Sharpening  Lathe  Tools    69 

Tools  for  Measuring  Turned  Work  70 

CHAPTER  V.— INTRODUCTION  TO   PATTERN-MAKING 72 

CHAPTER  VI.— MOLDING   77 

CHAPTER  VII.— GENERAL  PRINCIPLES  83 

CHAPTER  VIII.— MATERIALS    91 

Sandpaper,  Glue,  Varnish,  Beeswax,  Nails. 

CHAPTER  IX.— FILLETS    101 

CHAPTER  X.— CORES  107 

CHAPTER  XI. — MOULDERS'  JOINTS  OR  PARTINGS 116 

CHAPTER  XII.— CONSTRUCTIONAL  JOINTS 125 

CHAPTER  XIIL— TYPICAL   PATTERNS    136 

7 


8  CONTENTS 

CHAPTER  XIV— PULLEY   PATTERNS    163 

CHAPTER  XV.— PATTERNS  FOR  CAST  GEARS 182 

Bevel  Gear  Patterns  196 

CHAPTER  XVI.— PIPE  FITTINGS   202 

CHAPTER  XVII.— ESTIMATING  WEIGHT  OF  CASTINGS 209 

CHAPTER  XVIII.— MISCELLANEOUS  PATTERN  WORK 213 

Skeleton    Patterns    215 

Gluing  Feather-Edged   Board 219 

Large  Lathe  Chucks   221 

Lugs  or  Projections  for  Machinists'  Use .222 

Finishing    Patterns    225 

Loose  Pieces   227 

Standard  Patterns    229 

Stove  Pattern-Making 231 

INDEX    .  ...239 


CHAPTER  I 
HAND  TOOLS  FOR  WOODWORK 

For  all  handwork  the  bench  is  the  first  requisite. 
The  best  form  of  bench  for  pattern-making  is  that  illus- 
trated by  Fig.  i.  If  this  is  fitted  with  a  No.  i  Emmert 
Pattern-Maker's  Universal  Vise,  Fig.  2,  instead  of  the 
one  shown  at  the  head  of  the  bench,  it  will  be  the  best 


FIG.  1. 


that  can  be  obtained  for  this  part  of  the  shop  equip- 
ment for  pattern-making,  and  also  for  cabinet  making. 
The  bench-hook  is  a  very  useful  part  of  bench  equip- 
ment, one  form  of  which  is  shown  at  Fig.  3 ;  it  should 
be  12  to  14  inches  long.  Some  form  of  saw-horse  is 
also  a  necessary  part  of  the  pattern  shop  equipment ; 
a  handy  and  easily  built  form  is  shown  in  Fig  4.  An- 
other almost  indispensable  article,  something  like  a 


10 


WOOD  PATTERN-MAKING 


bench  in  its  nature,  is  what  is  known  as  a  laying  out 
table,  or  large  drawing  board,  on  which  work  can  be 
laid  out  full  size  when  necessary.  It  should  be  built 
very  solid,  and  have  a  top  that  is  a  true  plane.  This 


FIG.  3. 


FIG.  2. 


will  be  found  very  convenient  on  which  to  build  some 
classes  of  patterns,  for  by  using  this  they  may  be  built 
up  over  the  lines  laid  out,  as  is  sometimes  necessary. 
In  some  shops  this  laying  out  table  is  of  iron,  with  the 
top  planed  true. 


FIG.  4. 


MEASURING  AND  LINING  APPLIANCES 

The  standard  of  length  used  by  mechanics  and  en- 
gineers in  the  United  States  is  the  English  yard.  The 
standard  for  reference  is  the  "Troughton  Scale,"  a 
bronze  bar  with  an  inlaid  silver  scale,  made  for  the 
coast  survey  of  the  United  States,  by  Troughton,  of 
London.  This  was  adopted  as  the  standard  by  the 
Treasury  Department  in  1832,  on  the  recommendation 
of  Mr.  Hassler,  who  was  at  that  time  the  superinten- 
dent of  the  United  States  Coast  Survey.  The  meter 
has  since  been  made  the  legal  standard ;  the  act  of 
Congress  making  it  such  was  passed  July  27,  1866. 


FIG.  5. 

The  most  commonly  used  measuring  appliance,  how- 
ever, is  what  is  known  as  the  two  foot  rule.  This  is  a 
strip  of  wood,  usually  boxwood,  24  inches  long,  and 
about  ^  inch  wide.  For  convenience  in  carrying,  it  is 
jointed  so  that  it  can  be  folded  into  two  or  four  folds. 
These  rules  for  general  woodworkers'  use  are  gradu- 
ated in  i6ths  of  an  inch  on  one  side  and  8ths  of  an  inch 
on  the  other.  The  better  class  have  the  inside  of  each 
leg  graduated  in  loths  and  I2ths  of  an  inch,  Fig.  5. 
Another  form  of  rule  is  what  is  known  to  pattern- 
makers as  the  shrink  rule.  By  the  use  of  this  in  pat- 
tern-making, due  allowance  is  made  in  the  pattern  for 
the  shrinkage  that  will  take  place  in  the  metal  of  the 

11 


12  WOOD  PATTERN-MAKING 

casting.  The  common  form  of  this  rule  is  a  strip  of 
boxwood  il/4  inches  wide,  and  24*4  inches  long.  It 
is  divided  equally  into  twenty-four  parts,  and  each  one 
of  these  parts  is  subdivided  as  in  the  ordinary  two-foot 
rule. 

Another  measuring  instrument  that  is  very  useful  to 
all  woodworkers,  especially  to  those  having  much  lay- 
ing out  to  do,  is  the  framing  square.  This  consists  of 
two  flat,  thin  pieces  of  steel,  united  at  right  angles  to 
each  other.  One  piece  is  2  inches  wide  and  24  inches 
long;  the  other  i^>  inches  wide  and  17  inches  long,  Fig. 
6.  These  are  graduated  along  the  edges  of  the  flat  sides 
the  same  as  the  two-foot  rules ;  but  besides  these  grad- 
uations there  are  others  running  through  the  center  of 
the  sides.  On  one  side  of  this  blade,  as  the  wider  side  or 
leg  is  called,  is  the  Essex  board  measure,  which  is  very 
useful  for  reading  off  the  area  in  square  feet  of  a  board 
or  any  surface,  when  its  length  in  feet  and  its  width 
in  inches  are  known.  On  one  side  of  the  short  leg,  or 
tongue,  as  it  is  called,  is  the  brace  measure  table.  This 
table  is  composed  of  sets  of  three  figures,  two  of  which 
are  the  lengths  of  two  sides  of  a  right-angled  triangle, 
the  other  the  length  of  the  hypotenuse. 

The  use  of  the  Essex  board  measure  may  be  demon- 
strated by  working  the  simple  problem  of  finding  the 
number  of  feet  contained  in  a  board  of  certain  outside 
dimensions.  But  first  let  us  learn  what  is  meant  by 
the  term  "a  foot  of  lumber"  or  a  board  foot.  The  board 
foot  is  the  unit  used  in  computing  lumber  and  is  12 
inches  long  and  12  inches  wide  and  I  inch  thick,  so 
that  if  a  board  is  12  feet  long  and  12  inches  or  i  foot 
wide,  it  contains  12  feet  of  lumber  if  it  is  I  inch  thick ; 


FIG.  6. 


HAND  TOOLS  FOR  WOODWORK  13 


if  it  is  2  inches  thick  it  will  contain  24  feet ; 
if  3  inches  thick,  36  feet,  and  so  on. 

The  space  surface,  or  area,  12x12  inches, 
is  also  called  a  square  foot,  and  sometimes 
a  superficial  foot.  These  terms,  however, 
refer  only  to  the  surface,  and  in  no  way  do 
they  recognize  the  third  dimension  or  thick- 
ness. The  Essex  board  measure  as  it  ap- 
pears on  the  blade  of  the  steel  framing  square 
is  made  up  of  a  series  of  parallel  lines  or 
columns,  one  series  being  parallel  with  the 
edges  of  the  blade,  and  another  perpendicular 
to  these.  The  figures  representing  dimen- 
sions are  located  in  these  columns.  The  fig- 
ures on  the  outside  edge  of  the  blade,  i,  2, 
3,  and  so  on  up  to  24,  are  employed  to  rep- 
resent the  width  of  a  board  in  inches,  and 
all  the  lengths  in  feet,  included  in  the  table, 
in  the  column  under  figure  12  of  these  out- 
side graduations.  The  numbers  in  this- col- 
umn vary  somewhat  on  the  different  makes 
of  squares,  but  it  usually  contains  the  num- 
bers 8,  10,  14,  16,  and  18,  these  numbers 
representing  the  length  of  the  board  in 
feet.  It  should  be  noticed  that  these  num- 
bers represent  the  commercial  lengths  to 
which  most  lumber  is  cut,  and  to  be  found 


14  WOOD  PATTERN-MAKING 

in  all  lumber  dealers'  yards.  To  find  the  number  of 
board  feet  or  feet  of  lumber  in  any  board,  first  look  in 
the  column  of  the  outside  graduations  under  12  for  a 
number  representing  its  length  in  feet.  Having  found 
it,  pass  the  finger  along  on  the  same  line  until  it  comes 
under  the  figure  in  the  outside  graduations  that  corre- 
sponds to  the  width  of  the  board  in  inches.  The  figure 
on  this  line  nearest  the  finger  represents  the  number 
of  board  feet  the  board  contains  if  it  is  i  inch  thick. 


FIG.  7. 

Example  i :  How  many  feet  of  lumber  are  there  in  a 
board  10  feet  long,  7  inches  wide  and  i  inch  thick? 
Under  12  of  the  outside  graduations  the  10  is  on  the 
second  line,  and  the  figure  on  this  line  that  comes 
under  the  figure  7  is  5 — 10 — 5  feet  10  inches.  This 
example  may  be  stated  and  worked  in  figures  thus : 
10X7=70-^12=5—10. 

Example  2 :  What  is  the  superficial  area  of  a  board 
(or  any  surface)  whose  length  is  8  feet,  and  width  is 
21  inches.  As  in  example  i,  look  under  12  of  the  out- 
side graduations  for  the  figure  8.  On  this  line,  under 
the  number  21,  will  be  found  14,  which  represents  the 
area  in  feet.  Again,  8X2i=i68-=-i2=i4. 


HAND  TOOLS  FOR  WOODWORK 


15 


This  scale  may  be  used  to  find  the  area  of  any  surface 
within  its  limits  when  the  length  of  the  surface  in  feet 
and  its  width  in  inches  are  known. 


FIG.  8. 


A  try-square  is  shown  by  Fig.  7.    The  beam  A  is  of 
wood,  faced  with  a  strip  of  brass  to  protect  it  from  wear. 


FIG.  9. 


The  blade  B,  at  right  angles  to  the  beam  is  of  steel.  In 
some  try-squares  the  blade  is  graduated.  Some  try- 
squares  are  made  entirely  of  metal.  Fig.  8  represents 
a  combination  square ;  the  blade  is  movable  so  it  can 


16  WOOD  PATTERN-MAKING 

be  used  at  any  length  on  either  side  of  the  head.  The 
bevel,  Fig.  9,  sometimes  improperly  called  a  bevel 
square,  is  made  up  of  parts  which  are  similar  to  those 
of  the  try-square,  and  have  the  same  names.  The 
blade  is  adjustable  to  any  angle  with  the  beam,  and 
.when  set,  the  thumb-screw  fastens  it.  The  size  of  both 
square  and  bevel  is  expressed  by  the  length  of  the  blade 
in  inches.  The  miter-square  is  similar  to  the  try-square, 


FIG.  10. 

but  has  the  blade  set  permanently  at  an  angle  of  45° 
to  the  stock  or  beam. 

The  dividers  are  used  in  spacing  and  laying  out 
circles.  They  are  also  very  useful  for  laying  out  and 
transferring  angles.  One  way  of  using  them  for  this 
purpose  is  illustrated  in  Fig.  10,  which  shows  how  to 
set  a  bevel  at  an  angle  of  60°  and  120°.  To  do  this,  take 
a  board  that  has  been  planed  flat,  and  one  edge  jointed  ; 
that  is,  planed  straight.  Gage  a  line  at  any  distance 
from  this  straight  edge.  From  any  point  on  this  line, 
with  any  radius,  use  the  dividers  to  make  the  arc  C. 
With  same  radius  from  B  make  the  arc  D.  Now  draw 


HAND  TOOLS  FOR  WOODWORK  17 

a  line  passing  through  the  intersection  of  C  and  D  and 
the  point  first  selected  on  the  line  AB.  This  line  will 
make  an  angle  of  60°  with  the  edge  of  the  board  if 
measured  on  one  side,  and  120°  if  measured  on  the  other. 


FIG.  11. 

To  set  the  bevel,  place  the  stock  or  beam  against  the 
edge  of  the  board  and  swing  the  blade  until  it  exactly 
coincides  with  the  line. 

Fig.  1 1  shows  the  usual  form  of  marking  gage.    The 
steel  spur  should  be  filed  to  a  thin  cutting  edge ;  the 


FIG.  12. 


long  way  of  this  edge  is  to  stand  at  or  near  right  angles 
to  the  beam  in  such  a  way  that  when  pushed  along 
with  the  left  hand,  its  tendency  will  be  to  pull  the 
gage  onto  the  piece  gaged.  The  square-shaped  piece 
through  which  the  beam  slides  is  called  the  head.  The 
graduations  on  the  beam  are  not  to  be  depended  on  for 


18  WOOD  PATTERN-MAKING 

accurate  measurements.  The  mortise  gage  has  two 
spurs ;  one  of  them  is  movable  on  the  beam,  being 
fastened  to  a  brass  slide  that  is  moved  back  and  forth 
by  a  thumb-screw  at  the  end  of  the  beam.  This  is 
shown  at  Fig.  12. 


CHISELS  AND  CHISEL-LIKE  TOOLS 

There  are  two  general  forms  of  chisels  used  by  wood- 
workers, viz.,  the  tanged  or  shank,  and  the  socket. 
These  terms  refer  to  the  style  of  handle  and  to  the  way 
it  is  fastened  to  the  chisel.  Almost  all  chisels  are  now 
made  entirely  of  steel.  The  tanged  form  is  shown  in 


FIG.  13. 

Fig.  13,  and  is  called  a  firmer  chisel.  It  has  a  long 
tongue  or  tang  which  is  driven  into  the  handle,  the 
bolster  coming  up  against  the  end  of  the  handle,  and 
so  preventing  its  being  driven  further  in.  It  is  this 


FIG.  14. 


form  of  chisel  that  is  usually  used  by  workers  in  soft 
woods,  such  as  joiners  and  pattern-makers.  The  better 
quality  of  this  form  of  chisel  has  beveled  edges  as 
shown  in  Fig.  13.  The  other  form,  known  as  the  socket 
firmer,  is  shown  in  Fig.  14.  It  is  so  called  because  the 
handle  sets  into  a  socket  provided  for  it.  This  form  of 
chisel  is  more  generally  used  than  any  other,  as  all 
classes  of  woodworkers  except  joiners  and  pattern- 
makers employ  it  almost  exclusively,  while  even  some 

19 


20 


WOOD  PATTERN-MAKING 


of  these  prefer  this  kind  because  it  is  stronger  than  the 
tanged  firmer.  Socket  firmers  are  made  of  different 
weights  and  lengths  for  different  kinds  of  work.  The 
better  grades  of  these  also  are  made  with  beveled  edges. 


FIG.  16. 

Gouges  have  blades  that  are  curved  in  section 
throughout  their  length,  and  are  named  and  used  like 
chisels.  There  are  two  general  forms  of  this  tool,  viz : 
the  inside  gouge,  Fig.  15,  and  the  outside  gouge,  Fig. 
16.  The  bevel  of  the  first  is  ground  on  the  inside  of 
the  curve ;  that  of  the  other  on  the 
outside.  The  latter  is  generally  the 
more  useful.  The  straight  side,  that  is, 
the  side  opposite  the  bevel,  is  called  the 
back  in  all  chisels,  gouges  and  plane 
irons,  and  should  be  kept  perfectly 
straight,  not  beveled  in  the  slightest 
degree.  Gouges  can  be  bought  with  the 
cross  section  of  three  different  curva- 
tures, known  as  quick,  middle,  and  flat  sweep.  These 
are  shown  in  Fig.'i/,  which  represents  the  cutting  edge 


HAND  TOOLS  FOR  WOODWORK 


21 


of  each.  The  sizes  of  all  gouges  and  chisels  are  desig- 
nated by  the  width  of  the  blade  ;  a  2.  inch  chisel  or  gouge, 
for  instance,  has  a  blade  that  is  approximately  2.  inches 
wide.  They  are  made  in  sizes  as  follows :  from  ]/%  inch 
up  to  i  inch  by  8th  inches ;  from  I  inch  to  2  inches  by 
4th  inches. 


FIG.  18. 

The  drawing-knife,  or,  as  it  is  sometimes  called,  the 
draw-shave,  is  in  reality  a  very  wide  chisel,  but  is  not 
used  in  the  same  way.  It  is  shown  in  Fig.  18. 


SAWS 

The  saw  is  one  of  the  most  useful  and  effective 
woodworking  tools,  but  is  perhaps  the  most  difficult  to 
keep  in  good  order.  Saws  are  of  two  general  kinds — 
rip-saws  and  crosscut-saws.  The  rip-saw  is  intended 
to  cut  with  the  grain  of  the  wood,  the  crosscut-saw  is 
used  for  cutting  across  the  grain.  A  rip-saw  should  be 


FIG.  19. 


FIG.  20. 


from  24  inches  to  26  inches  long  and  should  have  from 
four  and  a  half  to  six  teeth  to  the  inch.  A  crosscut-saw 
for  bench  use,  is  called  a  panel-saw;  it  should  be  about 
20  inches  long,  and  should  have  from  eight  to  ten  teeth 
to  the  inch.  A  full-sized  crosscut-saw,  called  a  hand- 
saw, is  26  inches  long  and  should  have  from  seven  to 
nine  teeth  to  the  inch,  Fig.  19.  The  back-saw,  Fig.  20, 
is  a  crosscut-saw  with  a  very  thin  blade  and  fine  teeth ; 
the  blade  is  reinforced  with  a  strip  of  brass  or  steel 

22 


HAND  TOOLS  FOR  WOODWORK 


23 


along  its  back  edge,  hence  its  name.  The  keyhole-saw. 
Fig.  21  is  a  narrow-bladed  saw  used  for  entering  small 
holes  for  the  purpose  of  cutting  a  short  distance  until 
a  larger  saw  may  be  used,  or  for  cutting  along  curved 
lines.  Another  saw  that  is  sometimes  used  for  similar 
work  but  is  somewhat  larger,  is  called  a  compass-saw. 
Fig.  22.  The  keyhole  and  the  compass-saw  are  likely 


FIR.  21. 


FIG.  22. 


to  be  used  both  across  the  grain  and  with  the  grain, 
and  are  therefore  filed  differently  from  those  designed 
especially  for  just  one  of  these  purposes. 

As  the  rip-saw  has  to  cut  or  sever  the  ends  of  fibres 
of  the  wood,  its  teeth  should  have  chisel-like  points. 
The  crosscut-saw  has  also  to  sever  the  fibres  of  wood, 
but  in  a  different  way.  As  the  cutting  is  done  across 
the  fiber  of  the  wood,  it  requires  what  may  be  called 
a  scoring  of  the  fiber.  The  friction  of  the  other  parts 
of  the  teeth  on  the  wood  loosens  the  particles  cut  or 
separated,  and  carries  them  away  in  the  form  of  sawr 


24 


WOOD  PATTERN-MAKING 


dust.  The  size  of  the  teeth  is  governed  largely  by  the 
size  of  the  pieces  of  wood  to  be  sawn :  for  cutting  trees 
into  saw  logs  the  teeth  are  very  large ;  the  back-saw 
has  very  small  teeth  because  it  is  used  for  cutting  com- 
paratively small  pieces  of  lumber. 

In  the  actual  filing  of  saws  the  size  of  the  teeth  is 
determined  by  the  number  of  teeth  in  a  given  distance. 


FIG.  23. 


The  size  of  its  teeth,  other  things  being  equal,  does  not 
help  or  hinder  the  smooth  cutting  of  a  saw.  For  a  rip- 
saw the  best  form  of  tooth  is  a  chisel-pointed  one ;  the 
best  form  for  crosscutting  is  a  triangular-pointed  one. 
These  two  forms  of  teeth  are  shown  in  Figs.  23  and  24. 
The  angles  most  suitable  for  general  work  are  also 
indicated  in  the  same  figures,  Fig.  23  representing  the 
teeth  for  a  rip-saw  and  Fig.  24  the  teeth  for  a  crosscut- 
ting-saw.  These  should  be  varied  according  to  the  kind 
of  wood ;  they  should  be  less  acute  for  hard  wood  and 
more  acute  for  soft  wood.  The  keyhole-saw  and  com- 
pass-saw are  filed  with  a  combination  of  these  angles. 

In  fitting  or  sharpening  a  saw  for  use,  there  are  four 
distinct  operations  to  be  performed : 


HAND  TOOLS  FOR  WOODWORK  25 

i.  It  must  be  top-jointed;  that  is,  a  file  should  be 
passed  along  the  tops  of  the  teeth,  so  that  they  may  all  be 
of  the  same  height  and  extend  in  the  same  general  line, 
the  line  being  a  slight  curve.  Top-jointing  is  best  done 
with  a  flat  file  set  in  a  block  of  wood  as  shown  by  Fig. 
24  a.  In  use,  the  slot  A  is  set  over  the  saw  blade.  This 
holds  the  side  of  the  file  perpendicular  to  the  sides  of 


FIG.  24. 

the  saw  making  the  tops  of  the  teeth  square  with  those 
sides.  A  very  convenient  little  tool  for  this  purpose 
may  be  purchased  of  tool  dealers. 

2.  It  must  be  set;  that  is,  the  point  of  each  tooth  is 
bent  sidewise,  adjacent  teeth  being  bent  in  opposite 
directions.    This  is  done  so  that  the  saw  kerf  (as  the 
path  made  by  the  saw  in  passing  thru  the  wood  is 
called),  will  be  cut  wider  than  the  thickness  of  the 
saw  plate,  and  will  therefore  allow  the  saw  to  be  moved 
back  and  forth  without  sticking.    Setting  is  sometimes 
done  with  a  hammer  set,  but  usually  with  some  form 
of  plier  set,  of  which  there  are  several  good  ones  in  the 
market. 

3.  It  must  be  filed;  that  is,  the  individual  teeth  must 
be  filed  to  a  point.    This  must  be  done  very  carefully, 


26 


WOOD  PATTERN-MAKING 


having  the  saw  firmly  fastened  in  a  saw  clamp,  prefer- 
ably an  iron  one.  The  file  should  be  moved  over  the 
saw  with  a  firm,  steady  stroke,  as  nearly  the  whole 
length  of  the  file  as  possible,  and  with  just  enough 
pressure  and  no  more,  to  make  the  file  cut.  If  a  chat- 
tering noise  is  made  by  the  file  it  is  an  indication  that 
the  saw  is  improperly  supported,  or  that  the  file  is  dull. 


FIG.  24a. 

4.  It  should  be  side-jointed;  that  is,  a  file  or,  prefer- 
ably, an  oilstone  should  be  passed  along  the  side  of  the 
teeth,  which  will  even  up  the  set.  This  can  be  done 
very  readily  by  laying  the  saw  on  one  of  its  sides  on 
a  flat  board  or  on  the  bench  top  and  passing  an  ordi- 
nary oilstone  along  the  teeth,  care  being  taken  to  keep 
the  larger  part  of  the  oilstone  above  the  teeth  so  as 
not  to  round  off  their  points. 


BORING  TOOLS 

In  Fig.  25  is  shown  the  auger  bit.  This  is  the  Rus- 
sel  Jennings  pattern,  one  of  the  best  of  its  kind.  Fig. 
26  represents  what  is  called  a  square-hole  auger.  The 
boring  is  clone  by  a  common  auger  bit  on  the  inside 
of  a  thin  shell,  which  is  square ;  the  corners  are  sharp- 


FIG.  25.  FIG.  27.          FIG.  29.  FIG.  31. 

FIG.  26.  FIG.  28.  FIG.  30.  FIG.  32. 


ened,  and,  as  the  extra  long  spur  or  screw  on  the  end 
of  the  auger  draws  it  into  the  wood,  these  square  cor- 
ners cut  the  hole  made  by  the  auger  into  square  form. 
Fig.  27  is  the  Syracuse  drill-bit.  This  is  the  best  all- 
round  drill  for  wood.  Because  of  its  shape,  it  will  bore 
in  any  direction  of  the  grain,  and  it  will  also  operate 
close  to  the  end  of  a  piece  without  splitting  it.  If 


27 


28 


WOOD  PATTERN-MAKING 


it  becomes  dull  it  can  easily  be  sharpened.  In  Fig.  29 
is  shown  the  expansive  bit,  one  of  the  most  useful 
boring  tools,  because  of  its  range  in  size.  It  can  be  set 
to  bore  any  sized  hole  within  its  range.  Two  sizes  can 
be  purchased,  one  boring  holes  from  ^  inch  to  i^ 
inches,  and  the  other  from  %  inch  to  3  inches.  Fig.  28 


FIG.  33. 


shows  another  boring  tool  that  is  very  handy,  especially 
to  pattern-makers  and  to  others  who  want  to  bore  holes 
with  smooth  bottoms.  It  is  called  the  Forstner  bit. 
It  has  no  spur  or  leading  screw,  so  it  must  be  pushed 
to  its  work.  Fig.  30  is  what  is  known  as  a  center  bit. 
It  is  very  convenient  for  boring  holes  in  work,  as  it 
(the  work)  revolves  in  the  lathe.  The  central  spur  is 
not  a  screw,  but  simply  a  triangular  point,  so  that  this 
bit,  like  the  last  one,  must  be  forced  to  its  work;  thus 
it  can  be  made  to  do  its  work  rapidly  or  slowly  as  the 
job  may  demand. 

In  providing  holes  for  screws  it  is  found  to  be  almost 
necessary,  especially  in  hard  wood,  to  countersink  the 


HAND  TOOLS  FOR  WOODWORK  .29 

top  for  the  screw  head.  In  Fig.  31  is  represented  one 
form  of  tool  used  for  this  purpose ;  it  is  called  a  counter- 
sink. Fig.  32  shows  one  form  of  combination  drill  and 
countersink. 

In  Fig.  33  is  shown  one  of  the  best  forms  of  what  is 
called  a  bit-brace  or  bit-stock.  This  is  Fray's  rachet 
bit-brace.  For  general  use  the  auger-bit  is  preferred, 
as  when  sharp  it  will  cut  a  very  clean,  smooth  hole, 
and  do  it  rapidly.  In  boring  a  hole  through  a  piece  of 
wood  with  this  bit,  when  it  is  desired  to  leave  both  sides 
smooth,  care  should  be  taken  not  to  let  the  bit  go  clear 
through  from  one  side,  but  to  bore  just  far  enough  so 
that  half  the  length  of  the  screw  comes  through ;  then 
remove  the  bit  and  finish  the  hole  from  the  other  side. 
Another  way  this  may  be  done  is  to  clamp  a  piece  of 
waste  wood  to  one  side  of  the  piece  through  which  the 
hole  is  to  be  bored  before  boring  the  hole. 


MISCELLANEOUS  TOOLS 

Hand  screwdrivers  are  of  several  shapes.  Fig.  34 
shows  one  very  common  form  which  is  a  very  good 
one  for  the  bench  worker.  Some  of  the  other  forms 
are  better  for  special  uses.  The  part  of  a  screwdriver 
that  enters  the  slot  of  the  screw  head  should  never  be 
wedge-shaped ;  otherwise,  when  force  is  applied,  the 
tendency  is  to  lift  it  from  the  slot  instead  of  turning  the 


FIG.  34. 

screw.  The  correct  shape  is  shown  in  Fig.  34.  Brace 
screwdrivers  instead  of  having  a  handle,  are  provided 
with  a  shank  for  use  in  a  brace. 

A  hammer  and  a  mallet  are  needed  for  bench  work. 
The  square  form  of  mallet  is  for  some  reasons  the  best. 
What  is  known  as  the  claw-hammer  is  the  best  for 
general  bench  use.  The  nailset,  though  small,  is  a 
very  necessary  tool  for  bench  work. 

The  miter-box,  one  form  of  which  is  shown  in  Fig. 
35,  is  an  almost  indispensable  tool  for  bench  workers. 
It  is  the  most  useful  when  small  pieces  of  irregular 
outline,  such  as  mouldings,  have  to  be  cut  to  a  miter 

30 


HAND  TOOLS  FOR  WOODWORK 


.31 


line,  as  in  the  case  of  a  picture  frame,  for  instance. 
The  word  miter,  when  used  without  a  qualifying  word, 
is  understood  to  mean  the  intersecting  line  between 
any  two  pieces  of  wood  at  right  angles  to  each  other, 


FIG.  35. 


as  the  diagonal  of  a  square  which  makes  it  a  45°  miter. 
When  pieces  are  to  be  mitered  at  any  other  angle  than 
45°,  the  angle  of  the  intersecting  line  is  indicated  in 
degrees ;  for  instance,  a  sixty-degree  miter. 

When  pieces  of  wood  have  to  be  held  together  tem- 
porarily, for  gluing  or  any  other  purpose,  some  form 
of  clamp  is  necessary.  The  form  shown  in  Fig.  36, 
known  as  a  handscrew,  is  the  most  used  by  pattern- 
makers. In  using  handscrews  care  should  be  taken 


32 


WOOD  PATTERN-MAKING 


not  to  force  the  jaws  too  far  from  their  normal  parallel 
position ;  otherwise,  the  threads  of  the  screws  may  be 
stripped,  or  even  a  screw  broken.  There  are  several 
forms  of  iron  clamps  on  the  market,  one  of  the  best  of 


' 


I 


FIG.  36. 


FIG.  37. 

which  is  illustrated  by  Fig.  37.  These  are  sometimes 
very  useful,  but,  all  things  considered,  handscrews  are 
the  best  for  bench  work. 

A  grindstone  of  some  form  is  a  necessity  for  grind- 
ing the  cutting  edges  of  woodworking  tools.  It  should 
be  selected  with  reference  to  its  grit ;  one  that  is  rather 
fine  and  soft  is  best.  A  power  grindstone  should  have 
a  speed  of  from  500  to  600  peripheral  feet  per  minute, 
depending  upon  the  steadiness  and  accuracy  with 
which  it  runs.  When  a  stone  throws  water  from  its 
face  it  is  running  too  fast  for  doing  good  work  in  tool 
grinding. 


PLANES  AND   PLANE-LIKE  TOOLS 

A  bench-worker's  "set"  of  planes  consists  of  four, 
the  jointer,  the  short  jointer  or  fore-plane,  the  jack- 
plane  and  the  smoothing-plane.  To  separate  these  into 
a  class  they  are  usually  spoken  of  as  surfacing  planes. 
These  differ  in  length  from  8  inches  in  the  smooth- 
ing-plane to  30  inches  in  the  jointer. 

The  jack-plane  is  the  first  one  used  in  planing  a 
rough  surface,  or  in  removing  surplus  material.  If 
the  surface  is  simply  to  be  smoothed,  then  the  smooth- 
ing-plane may  immediately  follow  the  jack-plane ;  but 
if  a  true  surface  is  wanted  the  jack-plane  should  be 
first  followed  by  the  short  jointer,  and  then  by  the 
jointer.  With  the  last  named  plane  in  good  condition, 
practically  a  true  plane  surface  may  be  made.  The 
carpenter  or  joiner  would  call  this  a  surface  that  is 
out  of  wind. 

To  test  a  surface  during  the  process  of  planing, 
winding-sticks  or  strips  are  used.  A  winding-stick  is 
a  strip  of  wood  of  wedge-like  cross-section  about  two 
inches  wide,  and  with  both  edges  straight  and  parallel 
to  each  other.  Two  of  them  are  needed  to  test  a  sur- 
face, one  being  placed  near  each  end  of  it.  After  set- 
ting them  on  the  surface  exactly  parallel  to  each  other 
the  workman  should  sight  across  from  one  to  the  other. 
As  the  eye  is  lowered,  if  the  one  farther  away  is  lost 
sight  of  all  at  once,  the  surface,  if  straight  between 
the  points  on  which  the  strips  rest,  is  a  true  plane,  and 
is  said  to  be  out  of  wind.  If  the  farther  one  does  not 
disappear  all  at  once,  but  the  top  edges  appear  to  cross 
each  other,  then  the  surface  is  not  a  true  plane,  and  is 

33 


34  WOOD  PATTERN-MAKING 

spoken  of  as  a  winding  surface  or  in  wind.  If  the 
surface  is  in  wind,  notice  which  ends  of  the  winding 
sticks  are  the  higher.  Then,  if  a  true  surface  is  wanted, 
plane  off  some  of  the  surface  at  the  points  under  the 
higher  ends,  and  test  again.  In  order  to  obtain  the 
greatest  advantage  to  be  gained  from  the  use  of  wind- 
ing sticks,  they  should  be  considerably  longer  than  the 
width  of  the  surface  to  be  tested.  Thus  the  width  of 
the  surface  is  exaggerated,  which  is  one  object  sought 
in  using  these  strips.  The  blades  of  two  framing 
squares  answer  admirably  for  this  purpose. 

The  use  of  the  surfacing  planes,  especially  the  jointer, 
should  be  thoroughly  mastered,  so  that  the  surfaces  of 
any  piece  or  pieces  to  be  used  for  the  construction  of 
any  object  may  be  readily  and  correctly  planed.  As 
plane  surfaces  are  to  a  degree  the  foundation  for  the 
future  work  to  be  clone  on  them,  it  is  very  essential 
that  they  should  be  correct ;  otherwise,  poorly  fitting 
joints  will  result.  Good  work  cannot  be  done  if  the 
working  faces  are  incorrectly  planed.  In  order  to 
obtain  the  best  results  from  the  use  of  these  planes 
they  should  be  so  placed  and  held  on  the  surface  being 
planed  that  their  sides  are  parallel  with  the  direction 
of  the  motion  given  them  as  they  are  pushed  over  the 
surface.  This  is  particularly  true  of  narrow  surfaces 
such  as  the  edge  of  a  board.  If  this  one  principle  is 
applied  in  the  use  of  the  jointer,  and  the  jointer  is  at 
the  same  time  held  down  firmly  on  the  surface  being 
planed,  little  difficulty  will  be  experienced,  even  by  a 
beginner,  in  making  a  true  surface. 

The  cutting  irons  of  all  these  planes  are  true  cutting 
wedges  of  different  widths,  the  width  varying  with  the 


HAND  TOOLS  FOR  WOODWORK 


35 


length  of  the  plane.  To  each  of  these  cutting  wedges  is 
added  a  supplementary  iron  called  a  cap  or  back-iron, 
which  is  placed,  as  its  name  indicates,  on  the  back  of 
the  cutting  iron,  thus  making  it  a  double  iron.  The  pur- 
pose of  the  back-iron  is  to  break  the  shaving  as  it  is 
made  by  the  cutting  wedge. 

The  exact  way  in  which  this  is  done  can  be  explained 
better  with  a  cut  than  with  words  alone.    Fig.  38  shows 


FIG.  39. 


how  the  cutting  wedge  acts  as  a  single  iron.  In  Fig. 
39  is  shown  the  double  iron  and  the  effect  of  the  back- 
iron  on  the  shaving.  As  the  shaving  is  cut  and  bent 
by  the  cutting  wedge,  its  tendency  is  to  follow  the 
back  of  the  plane-iron  as  at  A,  Fig.  38.  As  seen  at  A, 
Fig.  39,  the  back-iron  prevents  this,  by  changing  its 
couise  and  breaking  it  before  it  has  time  to  split  down 
into  the  wood.  The  single  iron  does  very  good  work 
so  long  as  the  grain  is  favorable,  but  when  it  comes  to 
a  place  on  the  board  that  is  cross-grained,  as  at  B,  the 
shaving  will  split  ahead  of  the  cutting  iron  and  leave 
the  surface  rough. 

Fig.  40  shows  the  wood  plane  and  the  advantage  of 
a  narrow  mouth,  which  the  iron-plane  shown  in  Fig. 
39  lacks.  This,  too,  changes  the  direction  of  the  shav- 


36 


WOOD  PATTERN-MAKING 


ing.  It  has  also  the  advantage  that  it  aids  the  plane  in 
doing  smooth  work  at  a  spot  where  the  lumber  is  cross- 
grained  because  the  wood  directly  in  front  of  the  nar- 
row mouth  holds  down  the  wood  being  planed  im- 
mediately in  front  of  the  cutting  iron,  and  so  prevents 
its  being  torn  up  before  it  is  cut.  This  is  one  of  the 
advantages  that  the  wood  plane  has  over  the  iron ; 
another  is  the  comparative  ease  of  working.  Still, 


FIG.  40. 


when  everything  is  considered,  iron  planes  are  the 
best.  Their  principal  advantage  is  that  they  will  not 
warp  or  appreciably  wear;  consequently  the  face  or 
sole  of  the  plane  is  always  a  true  plane  surface. 

The  cutting  edge  of  plane-irons  should  not  be  straight 
but  slightly  curved.  For  the  jack-plane  this  curve 
ought  to  be  much  quicker  than  for  the  other  planes. 
The  jack-plane  is  frequently  used  for  removing  very 
thick  shavings,  and  if  the  iron  was  straight,  it  would 
tear  out  a  rectangular  groove  for  the  whole  width  of 
the  iron.  This  would  be  very  likely  to  clog  the  plane, 
and  would  also  consume  much  more  force  than  if  the 
edge  was  curved.  In  a  given  time  with  a  given  amount 
of  force  applied,  much  more  wood  can  be  removed  if 
the  iron  is  curved  than  if  it  is  straight. 


HAND  TOOLS  FOR  WOODWORK 


37 


Theoretically,  the  outline  of  the  cutting  edge  for  the 
jointer,  and  smoothing-plane  irons  should  be  straight 
in  order  to  produce  a  straight  flat  surface,  but  in  prac- 
tice this  is  not  the  case.  On  these  irons  the  corners 
should  be  slightly  rounded,  or,  what  is  better,  be 


FIG.  41. 

slightly  curved  the  whole  length  of  the  edge,  but  the 
radius  of  the  curve  should  be  much  larger  than  the 
jack-plane  iron. 

Fig.  41  shows  the  iron  jack-plane ;  the  other  three 
of  the  set  are  of  the  same  shape.     Fig.  42  shows  one 


FIG.  42. 


form  of  the  block-plane.  The  principal  use  of  this 
plane  is  to  smooth  end  grain.  The  angle  at  which  the 
iron  is  set  in  this  plane  is  much  smaller  than  that  of 
other  planes.  This  being  the  case,  the  iron,  which  is 
always  a  single  one,  is  inverted.  If  it  were  not  in- 
verted, the  angle  of  the  cutting  wedge  would  have  to 
be  so  small  that  it  would  not  stand  up  to  the  work. 


38 


WOOD  PATTERN-MAKING 


To  prevent  this  plane  from  breaking  the  corners  of 
the  wood,  when  being  used  on  the  end  of  a  board, 
another  piece  should  be  placed  back  of  the  one  being 


FIG.  43. 

planed.    If  the  board  is  of  considerable  width  the  plane 
may  be  worked  from  both  edges  and  not  carried  clear 


FIG.  44. 


Another  plane  that  is  very  useful  to  woodworkers 
is  shown  at  Fig.  43,  called  a  rabbet  plane.  The  iron  is 
set  askew  in  the  plane,  and  extends  the  whole  width 
of  the  face.  It  is  used  for  cutting  a  rectangular  space 
called  a  rabbet,  into  the  corner  of  a  piece  of  wood. 


HAND  TOOLS  FOR  WOODWORK 


39 


Another  plane-like  tool  is  illustrated  by  Fig.  44. 
This  is  the  carpenter's  plow.  Its  principal  use  is  the 
cutting  of  rectangular  grooves  into  wood  parallel  with 
the  grain.  It  is  adjustable  and  can  be  set  to  cut  the 
groove  at  any  distance  from  the  face  of  a  board.  Irons 


FIG.  45. 


of  different  widths  are  supplied  so  that  grooves  of  any 
widtli  and  depth  within  their  range  may  be  cut. 

A  plane  called  a  dado  plane,  shown  at  Fig.  45,  is 
used  for  cutting  rectangular  grooves  crossways  of  the 


grain.  Its  iron  is  set  askew.  It  has  a  depth  gage  to 
regulate  the  depth  of  the  groove.  Combination  planes 
made  of  metal,  which  may  be  used  in  the  place  of  the 
plow,  dado,  matching  planes,  beading  planes,  etc.,  are 
on  the  market  and  some  of  them  are  very  serviceable 
tools. 


40 


WOOD  PATTERN-MAKING 


Spoke-shaves  have  the  action  of  planes  but  are  not 
usually  classed  with  them.  A  simple  form  is  shown 
at  Fig.  46.  It  has  a  very  small  face  which  adapts  it 
for  use  on  irregular  surfaces.  There  are  several  other 
forms  of  planes  in  use,  but  most  of  them  are  designed 


lie.  48. 

for  specific  uses,  and  are  not  commonly  used  by  the 
pattern-maker. 

There  is  one  plane,  however,  used  by  pattern-makers, 
which  is  mentioned  in  another  chapter,  and  there  repre- 
sented in  the  wooden  form,  that  should  be  noticed  here, 
namely,  the  latest  form  of  iron  core-box  plane,  repre- 
sented in  Fig.  48. 


CUTTING   WEDGES 

Fiom  the  woodworker's  point  of  view,  the  chisel  is 
the  typical  cutting  tool.  It  has  two  operations  to  per- 
form when  in  action,  viz. :  cutting  the  fiber  of  the  wood, 
and  breaking,  crushing  to  one  side,  or  bending  the  wood 
out  of  the  way,  so  that  the  cutting  edge  may  go  on  with 
its  work.  Every  cutting  tool  is  a  wedge,  more  or  less 
acute.  To  widen  the  cut  the  wood  must  be  bent;  this 
the  cutting  wedge  of  the  plane  does,  and  thus  forms  a 
shaving.  The  chisel,  when  driven  into  the  wood,  as  in 
cutting  a  mortise,  crushes  the  wood  and  so  widens  the 
cut.  When  the  wedge  is  driven  in  parallel  with  the 
grain,  the  fibres  are  pressed  apart,  the  cut  is  widened 
and  the  wood  split-.  It  can  be  demonstrated  that  much 
less  force  is  required  to  carry  the  wedge  forward  when 
first  entering  the  cut  than  after  it  has  extended  into  the 
material  for  some  distance.  It  is  reasonable,  therefore, 
to  suppose  that  the  larger  part  of  the  force  applied  to 
form  a  shaving  or  chip,  is  consumed  in  this  bending  or 
crushing,  and  a  very  small  part  in  the  actual  cutting  of 
the  fiber  of  the  wood.  A  very  acute-angled  wedge  will 
do  a  given  amount  of  work  with  less  force  than  one  not 
so  acute.  But  the  one  with  the  larger  angle  will  do  the 
actual  cutting  as  easily  as  the  other.  The  angle  of  the 
wedge  has  very  little  to  do  with  the  force  required  to  do 
the  cutting,  at  least  up  to  any  angle  that  would  or  could 
be  used  for  cutting  wood.  The  acuteness  is  limited  only 
by  the  strength  of  the  steel,  so  it  must  vary  as  the  kind 
of  work  and  material  varies.  A  more  acute  one  may  be 
used  for  soft  wood  than  for  hard  wood.  And  again,  a 
larger-angled  wedge  is  needed  in  a  chisel  that  is  to  be 

41 


42  WOOD  PATTERN-MAKING 

used  or  driven  to  its  work  with  the  mallet  than  in  one 
that  is  to  be  used  with  the  hands  only. 

If  it  was  insisted  that  a  cutting  wedge  should  always 
have  its  maximum  of  delicacy,  it  would  necessitate  that 
the  angle  be  changed  for  almost  every  shaving  or  chip 
made.  This  would  be  impracticable,  so  that  the  results 
of  the  experience  of  woodworkers  may  be  expressed  as 
follows :  "Make  the  cutting  wedge  as  acute  as  the 
metal  will  allow  without  breaking,  when  fairly  used." 
The  angle  of  the  wedge  for  all  wood-cutting  tools  for 
general  use  should  be  from  22°  to  30°. 


FIG.  49. 

The  sharpening  of  a  cutting  wedge  requires  consider- 
able care  and  skill,  if  first-class  work  is  to  be  done  with 
it.  If  the  chisel  or  other  edge  tool  is  new,  or  very  dull, 
it  must  first  be  ground.  This  is  best  done  on  a  medium 
grit,  soft  grindstone.  Emery  wheels  are  largely  taking 
the  place  of  grindstones  for  this  purpose.  Greater  care 
is  necessary  in  the  use  of  emery  wheels  than  with  grind- 
stones for  grinding  woodworking  tools,  for  the  wedge 
being  thin,  the  temper  of  the  steel  is  very  liable  to  be 
drawn  by  the  heat  generated  by  the  friction.  In  grind- 
ing a  cutting  wedge,  the  grindstone  should  revolve 
toward  the  cutting  edge.  The  correct  position  in  this 
regard,  and  also  to  produce  the  best  angle  for  general 
use  is  shown  in  Fig.  49.  Plently  of  water  must  be  kept 


HAND  TOOLS  FOR  WOODWORK  43 

on  the  stone  during  the  process  of  grinding.  The  water 
serves  two  purposes ;  one  is  to  reduce  the  temperature 
generated  by  friction,  the  other  to  keep  the  stone  clean 
or  to  carry  off  the  particles  of  sand  and  metal  loosened 
in  the  process  of  grinding.  The  surface  produced  by 
the  grinding  is  called  the  bevel. 

As  the  coarse  grit  of  the  grindstone  will  not  produce 
a  clean,  smooth  cutting  edge ;  the  tool  will  have  to  be 
whetted.  This  is  done  on  an  oilstone,  either  natural  or 
artificial.  The  latter  kind,  if  made  by  a  reliable  firm, 
is  better,  as  it  wears  more  evenly.  The  tool,  while  held 
in  such  a  position  that  the  heel  of  the  wedge  does  not 
quite  touch  the  stone,  should  be  carried  back  and  forth 
along  the  whole  length  of  it,  care  being  taken  not  to 
give  the  tool  a  rocking  motion,  which  would  produce  a 
curved  instead  of  a  straight  line.  This  operation  should 
be  continued  until  a  slight  wire  edge  is  produced  on  the 
back,  as  the  straight  side  is  called.  The  wire  edge  must 
be  removed  in  order  to  produce  a  sharp  edge  that  will 
cut  smoothly.  To  do  this,  lay  the  tool  on  its  back,  flat 
on  the  oilstone,  and  give  it  a  few  light  strokes  toward 
the  edge,  from  the  operator.  Great  care  should  be  taken 
not  to  raise  the  handle  of  the  tool,  as  that  would  bevel 
this  side  of  the  wedge  and  impair  the  proper  working 
of  the  tool.  There  are  two  tests  that  may  be  used  to 
determine  whether  the  edge  is  sharp  ;  one  by  the  eye,  the 
other  by  the  sense  of  touch.  If  a  sharp  edge  is  examined 
by  the  eye,  it  will  be  noticed  that  a  dull  line  appears 
where  the  edge  is.  If  the  edge  is  not  sharp,  a  bright  line 
will  be  seen.  The  more  dull  the  tool  is,  the  larger  the 
bright  line  will  appear.  •  To  test  by  the  sense  of  touch, 
place  the  thumb  or  finger  on  the  edge,  and  try  to  move  it 


44  WOOD  PATTERN-MAKING 

along  the  edge.  If  it  is  not  sharp,  no  difficulty  will  be 
found  in  doing  this.  If,  however,  the  edge  is  sharp,  a 
clinging  or  pulling  sensation  will  be  felt.  The  best 
test,  however,  is  to  cut  wood  in  the  same  direction  as 
the  work  to  be  done.  If  the  surface  cut  is  smooth  and 
glossy,  the  tool  is  sharp.  If  the  tool  is  dull  it  will  cut 
a  surface  that  is  rough  and  dull  to  both  touch  and  sight. 


LAYING  OUT  WORK 

The  production  and  location  of  lines  is  one  of  the 
most  important  parts  of  woodwork,  as  of  all  mechanical 
work,  in  the  production  of  work  of  a  definite  size  and 
shape.  Any  carelessness  in  this  direction  will  always 
make  itself  manifest  in  the  finished  product.  This  is  so 
much  the  case  that  one  who  is  habitually  careless  in 
this  regard  seldom  makes  a  good  mechanic.  Let  it  be 
understood  at  the  outset  that  a  scratch  is  not  a  line,  and 
that  patience  and  accuracy  in  the  making  and  locating 
of  lines  is  one  of  the  first  requisites  to  success  in  all 
mechanical  manipulations,  and  in  the  production  of  all 
articles  made  by  mechanical  processes. 

The  tools  used  for  making  lines  are  four, — the  chalk 
line,  pencil,  gage  and  knife.  For  bench  work  the  knife 
and  gage  are  the  most  used.  The  knife  is  used  for 
marking  across  the  grain,  and  should  have  a  sharp 
point  so  that  it  will  cut  into  the  wood,  not  merely  scratch 
it.  In  making  a  mark  where  a  cut  is  to  be  made  with  a 
saw,  it  is  advantageous  to  cut  the  lines  about  &  of  an 
inch  deep.  If  this  is  done  and  the  saw  kerf  made  close 
up  to  it,  the  side  that  is  left  makes  a  nice  clean  surface 
to  abut  against  another  piece,  for  instance  the  shoulder 
of  a  mortise-and-tenon  joint.  The  gage  is  the  best  im- 
plement for  marking  lines  lengthwise  of  the  grain.  A 
great  deal  more  might  be  said  about  this  part  of  wood- 
working, — laying  out  work,  as  it  is  usually  called — but 
lack  of  space  forbids. 


45 


CHAPTER  II 
LUMBER 

Lumber  is  produced  by  sawing  trunks  of  trees 
lengthwise  into  planks  or  boards  of  commercial  sizes. 
In  order  to  produce  special  sizes  and  shapes,  the  saw- 
ing is  done  in  several  different  ways  without  regard  to 
the  grain  of  the  wood.  There  are,  however,  two  general 
methods  used,  by  one  or  the  other  of  which  the  larger 
part  of  all  lumber  is  produced.  One  of  these  is  called 
straight  or  bastard  sawing;  the  other  quarter-sawing. 
Straight  sawn  lumber,  sometimes  called  "rift  sawn,'' 
is  produced  by  passing  the  saw  thru  and  thru  the  log, 
without  any  regard  to  the  grain.  Quarter-sawn  lum- 
ber is  made  by  passing  the  saw  through  the  log  approx- 
imately parallel  with  the  medullary  rays,  or  radially 
with  the  log.  There  are  several  ways  of  doing  this, 
one  of  which  is  as  follows :  The  log  is  first  squared 
and  then  sawn  into  four  quarters.  Each  one  of  these  is 
set  on  the  carriage  of  the  sawing  machine  so  that  the 
saw  will  pass  thru  it  diagonally.  The  sides  of  the  center 
board  will  then  be  parallel  with  the  medullary  ray. 
This  method  gave  rise  to  the  term  "quarter-sawn." 
The  larger  part  of  all  quarter-sawn  lumber  produced 
is  made  by  this  method,  and  other  similar  ways  that 
vary  with  the  requirements  of  the  consumer.  What 
is  known  as  No.  i  quarter-sawn  lumber  has  one  side 
of  each  board  sawn  radially  to  the  log  and  therefore  is 
parallel  to  the  medullary  ray,  or  as  near  as  can  be  if 
the  crookedness  of  the  ray  is  considered.  This  last 

46 


LUMBER  47 

mentioned  method  is  very  wasteful  of  timber,  there- 
fore the  product  is  much  more  expensive  than  lumber 
sawn  in  other  ways. 

If  the  trunk  of  a  tree  is  cut  transversely,  it  is  found 
to  be  composed  of  a  series  of  concentric  cylindrical  lay- 
ers, the  cross  sections  of  which  form  rings  that  are  quite 
distinct  from  each  other.  These  layers  are  formed,  one 
each  year,  during  the  period  of  the  tree's  growth.  They 
vary  in  thickness  in  different  kinds  of  wood,  and  in 
different  specimens  of  the  same  kind.  They  also  vary 
in  density  and  color;  the  more  dense  or  hard  are  always 
found  near  the  heart.  These  variations  are  due  to  the 
difference  in  rapidity  of  growth,  length  of  season,  and 
other  circumstances  that  may  change  from  year  to  year. 
The  location  and  soil  in  which  the  tree  grew  also  modify 
to  a  degree  the  above  characteristics  of  these  layers.  It 
is  these  layers  of  woody  fiber  that  give  to  boards  the 
appearance  called  the  grain.  This  appearance  varies 
according  to  the  position  the  board  occupied  in  the  log. 
The  part  of  the  wood  next  to  the  bark  is  called  sap- 
wood;  all  on  the  inside  of  this  is  called  heart-wood. 
Heart-wood  is  generally  more  dense,  of  a  darker  color, 
and  is  much  more  durable  than  sap-wood.  During 
favorable  weather  the  sap  of  the  tree  circulates  through 
the  sap-wood,  but  during  the  winter  it  is  supposed  to 
cease ;  it  is  this  period  of  non-circulation  of  sap  that 
causes  the  distinct  lines  that  appear  between  succes- 
sive annual  rings.  The  darker  color  and  greater  density 
of  heart-wood  is  caused  by  the  closing  up  of  its  cells 
by  the  gums  of  the  wood  which  were  previously  held 
in  solution.  For  this  reason  it  is  nearly  or  quite  im- 
pervious to  sap.  There  is  a  difference  in  the  proper- 


48  WOOD  PATTERN-MAKING 

tion  of  sap-wood  in  different  kinds  of  trees,  and  in  dif- 
ferent individual  trees  of  the  same  species.  The  slower 
growing  trees  usually  have  the  least. 

For  a  tree  to  afford  the  best  quality  of  lumber  it 
should  not  be  cut  until  it  has  arrived  at  maturity.  The 
oak  is  said  to  reach  this  period  in  about  100  years,  the 
pine  in  70  to  100  years,  and  ash  and  elm  at  from  50  to 
100  years.  Midwinter  or  midsummer  are  the  seasons 
of  the  -year  best  adapted  for  the  felling  of  timber  to 
secure  the  best  quality  of  lumber.  The  principal  rea- 
son for  this  is  the  fact  that  at  these  seasons  the  trunk 
of  the  tree  contains  less  sap  than  at  others. 

Seasoning  lumber  is  driving  out  the  sap  from  its  pores. 
This  may  be  done  by  natural  or  artificial  means.  How- 
ever it  is  done  it  should  be  a  slow  process,  especially 
in  its  first  stages ;  therefore,  natural,  or  air  seasoning, 
gives  the  best  results.  For  any  purpose  where  strength 
or  permanence  of  form  is  very  desirable,  it  is  best  to 
properly  stick  up  the  lumber  in  a  seasoning  shed  that 
will  protect  it  from  the  sun,  rain,  and  snow,  for  at  least 
one  year,  and  then  put  it  in  a  drying  kiln  to  complete 
the  process.  If  lumber  is  put  into  the  kiln  when  green, 
the  sap  is  driven  out  so  rapidly  by  the  high  temperature 
that  it  carries  with  it  more  or  less  of  the  gums  of  the 
wood.  This  is  prevented  by  sticking  up  in  the  shed,  as 
during  the  time  it  is  under  these  natural  conditions  the 
process  is  comparatively  very  slow.  All  these  gums 
should  be  retained,  if  possible,  as  they  add  strength  and 
density  to  the  lumber ;  and  the  more  dense  wood  is, 
other  things  being  equal,  the  more  permanent  will  be  its 
form  under  varying  conditions  of  the  humidity  and  the 
temperature  of  the  surrounding  atmosphere.  Con- 


LUMBER  49 

versely,  then,  if  these  gums  are  driven  out  during  the 
process  of  seasoning,  the  wood  is  not  as  strong,  and  is 
more  porous,  also,  and  will  therefore  absorb  and  give 
off  moisture  more  readily,  which  will  interfere  with 
its  permanence  of  form.  Lumber  cannot  be  so  well 
seasoned  as  not  to  shrink  when  placed  in  a  dryer 
atmosphere. 

If  wood  is  placed  in  air  that  is  devoid  of  moisture, 
it  will  continue  to  retain  a  portion  of  its  original  moist- 
ure. A  log  taken  from  a  freshly  cut  tree  contains  about 
50  per  cent,  by  weight,  of  water.  (The  sap-wood  con- 
tains more  than  this  percentage,  the  heart-wood  less). 
When  the  log  (stripped  of  its  bark),  is  allowed  to  re- 
main in  the  open  air,  more  than  half  of  this  water  will 
evaporate  in  a  few  months.  If  it  is  sawn  into  lumber 
and  stuck  up  in  a  seasoning  shed,  the  water  will  be 
further  reduced  to  from  12  to  15  per  cent,  of  the  total 
weight ;  if  it  is  put  into  an  ordinary  living  room  it  will 
be  reduced  to  from  8  to  10  per  cent;  if  it  is  put  into  a 
drying  kiln  operating  at  a  temperature  of  from  160°  to 
180°  F.,  only  from  2  to  4  per  cent,  of  water  will  be  left ; 
but  tho  the  temperature  be  raised  to  300°  F.  (when 
chemical  destruction  begins),  water  will  still  be  given 
off.  Immediately  after  wood  is  taken  out  of  a  kiln 
it  begins  to  absorb  moisture.  In  a  week  it  will  have 
regained  from  5  to  6  per  cent  of  moisture ;  in  a  month 
or  so,  its  condition,  if  kept  in  the  open  air,  will  be 
normal — that  is,  12  per  cent  of  its  weight  will  be  due 
to  the  water  it  contains.  Whenever  wood  gives  off 
moisture  it  shrinks.  Green  wood  will,  in  seasoning, 
shrink  about  8  per  cent  of  its  width  across  the  grain. 
One  of  the  objects  of  seasoning  is  to  reduce  the  moist- 


50  WOOD  PATTERN-MAKING 

ure  to  the  proportional  limit  that  will  obtain  between 
the  wood  and  the  air  with  which  it  will  be  surrounded 
after  it  is  manufactured  into  some  article  of  use  or 
ornament.  Neither  air  seasoning  nor  kiln-drying  at 
a  temperature  below  200°  F.,  will  affect  the  capacity  of 
wood  for  taking  up  moisture  when  there  is  an  excess 
of  humidity  in  the  air,  and  whenever  wood  takes  up 
moisture  it  increases  in  size  (swells). 

This  faculty  in  wood  of  resuming  original  size,  of 
being  larger  or  smaller  according  to  atmospheric  con- 
ditions, is  one  of  the  most  difficult  problems  with  which 
woodworkers  have  to  deal.  To  paint  woodwork,  or  to 
varnish  it  makes  little  difference  to  these  qualities ; 
these  coatings  simply  retard  these  changes,  they  do  not 
overcome  them.  For  this  reason,  whenever  it  is  re- 
quired to  cover  large  areas  with  woodwork,  some 
method  must  be  adopted  to  nullify  the  effect  of,  or  of 
concealing  altogether,  the  "working"  of  the  various 
pieces  of  wood  after  they  are  placed  in  position.  The 
combined  precautions  of  intelligent  framing,  and  the 
application  of  protective  coatings  fail  to  secure  im- 
munity from  these  hygroscopic  effects.  Wood  is  doubly 
affected  by  the  cold,  damp  air  of  the  winter  months. 
By  the  natural  or  air  seasoning  process,  two  years  for 
small  or  thin,  and  four  years  for  large  or  thick  lumber, 
is  necessary  to  secure  good  results.  Lumber  is,  how- 
ever, rarely  overseasoned.  It  may  be  much  more 
rapidly  seasoned  by  high  temperatures  in  drying  kilns. 
It  is  not  impossible  to  season  i  inch  thick  boards  by 
this  means  in  two  days,  but  it  "kills  the  life"  of  the 
timber.  As  a  rule,  the  softer  a  wood  is,  the  more  readily 
it  will  shrink  or  swell.  Great  care  should  be  taken  in 


LUMBER  51 

preparing  the  foundation  on  which  to  pile  lumber  for 
the  purpose  of  seasoning  it  both  in  the  shed  and  dry 
kiln.  The  edges  of  the  timbers  on  which  the  boards  are 
laid  should  all  be  in  the  same  plane,  so  that  the  boards 
(which  will  retain  the  shape  given  to  them  by  the  pile), 
may  be  true  planes  when  taken  out  of  the  pile  after 
seasoning. 

Warping  in  wood  is  a  change  of  form  resulting 
from  unequal  shrinking  or  swelling.  It  is  sometimes 
caused  by  unequal  exposure ;  in  fact  this  is  its  most 
fruitful  cause.  When  a  board  is  so  placed  that  one  side 
is  exposed  to  the  direct  rays  of  the  sun  or  other  heat, 
and  the  other  to  a  damp  atmosphere,  the  first  side  will 
become  concave.  A  board,  especially  a  green  one,  will 
also  warp  when  it  is  equally  exposed,  that  is,  when  it 
is  surrounded  by  equally  dry  air.  The  cause  of  this  is, 
that  the  board,  because  of  the  arrangement  of  its  cells, 
gives  off  the  moisture  it  contains  more  rapidly  from 
one  side  than  the  other.  The  side  that  dries  first  will 
become  concave.  Now  if  a  board  is  cut  from  a  log 
midway  between  the  heart  and  sap,  there  will  be  a 
larger  number  of  the  cells  (which  lie  parallel  to  the 
sides  of  the  annual  layers),  opened  on  the  sap  side; 
therefore,  moisture  will  be  given  off  more  rapidly  from 
that  side,  and,  as  wood  always  shrinks  when  it  gives  off 
moisture,  that  side  will  shrink  first  and  become  concave 
and  the  heart  side  convex.  The  medullary  rays,  as 
they  shrink,  also  conduce  to  this  form  in  a  slight  degree. 

If  these  facts  are  kept  in  mind,  and  the  end  of  a 
board  is  examined  it  may  be  known  in  what  direction 
the  board  will  warp  when  any  of  the  above  conditions 
obtain  as  to  its  surroundings.  Quarter-sawn  lumber 


52  WOOD  PATTERN-MAKING 

is  cut  radially  to  the  log,  and  so  does  not  contain  these 
characteristics,  therefore  will  not  warp  much.. 

From  these  facts,  then,  the  following  principle  may 
be  deduced :  In  all  woodwork,  the  heart  side  of  the 
board  should  always  be  placed  on  the  side  of  the  work 
that  will  be  the  most  exposed  to  any  change  that  is 
likely  to  take  place  in  the  surrounding  atmospheric 
conditions,  for  the  reason  that,  of  the  two  sides,  it  is 
the  least  susceptible  to  change. 

Because  of  the  above  noted  characteristics  of  wood, 
it  is  best  to  cut  the  pieces  to  be  used  in  any  construction 
roughly  to  size,  and  allow  them  to  stand  for  some  time 
before  they  are  cut  to  the  finished  size.  If  this  is  done, 
they  may  warp  into  a  more  permanent  form,  and  so  will 
be  less  likely  to  change  the  form  of  the  final  construc- 
tion. A  board  that  has  recently  been  planed  to  a  true 
surface  should  not  be  left  lying  flat  on  the  bench,  as  it 
will  warp  and  become  concave  on  the  upper  side.  This 
is  due  to  the  greater  exposure  of  the  upper  surface  com- 
pared with  the  under,  which  remained  in  contact  with 
the  bench.  A  board  that  has  been  planed  to  a  true  sur- 
face all  over,  should  be  left  on  its  edge  or  end. 


CHAPTER  III 
READING  WORKING  DRAWINGS 

Mechanical  drawing  has  been  defined  as  the  uni- 
versal language  of  the  engineer.  A  drawing  made  in 
one  country  can  be  read  and  worked  to  in  another;  that 
is,  the  drawing  proper.  Notes  on  the  drawing  in  the 
language  of  a  country  could  not  be  read  except  by  one 
acquainted  with  its  language ;  and,  the  unit  of  measure- 
ment also  might  be  different,  but  the  main  idea  repre- 
sented by  the  drawing  would  be  readily  apprehended. 

One  who  desires  to  read  working  drawings  and  get 
from  them  the  information  they  are  intended  to  convey, 
must  know  something  of  the  principles  underlying  their 
construction,  and  the  conventionalities  used.  All  work- 
ing drawings  are  made  on  the  principle,  of  orthographic 
projection,  and  are  usually  spoken  of  simply  as  projec- 
tion drawings.  That  is,  all  the  imaginary  lines  of  sight, 
(projectors),  are  parallel,  and  perpendicular  to  the 
picture  plane.  There  are  three  principal  views  used 
in  the  representation  of  objects  by  drawings,  viz.:  the 
plan  or  top  view,  the  front  view,  and  the  end  or  side 
view.  It  is  sometimes  necessary  to  introduce  a  fourth 
view,  which  becomes  a  second  end  or  side  view.  Each 
of  these  views  is  drawn  so  as  to  represent  the  different 
sides  of  the  object  at  right  angles  to  each  other.  When 
some  parts  of  an  object  extend  at  an  angle  other  than 
a  right  angle,  auxiliary  views  are  projected  on  the  cen- 
ter lines  of  these  angular  parts,  in  order  to  show  their 

53 


54  WOOD  PATTERN-MAKING 

true  shape.  In  the  representation  of  simple  or  sym- 
metrical objects,  one  view  is  omitted,  usually  the  plan, 
as  it  is  not  necessary.  Many  objects  or  parts  of  ma- 
chinery, with  which  the  pattern-maker  has  most  to  do, 
can  be  represented  with  sufficient  clearness  by  two 
views.  When  these  do  not  clearly  delineate  the  object, 
the  third,  and,  if  necessary,  a  fourth,  is  used. 

The  obscured  parts  of  a  simple  object,  that  is,  parts 
that  do  not  appear  on  the  surface  represented,  are 
shown  by  broken  lines.  In  complicated  objects  this  is 
not  practicable  because  of  the  many  lines  that  become 
necessary,  which  would  be  confusing  and  lead  to  mis- 
takes. When  for  this  reason  this  method  of  broken 
lines  is  not  feasible,  it  is  customary  to  imagine  the 
object  cut,  or  that  an  assumed  plane  has  been  passed 
through  it,  and  the  surface  thus  produced  exposed.  A 
drawing  of  such  a  surface  is  called  a  section,  and  indi- 
cates the  shape  of  a  piece  at  the  place  cut  by  the  imag- 
inary plane.  A  piece  of  varying  section  may  be  imag- 
ined to  be  cut  by  planes  at  as  many  places  as  is  desired. 
and  the  section  shown  at  each.  Complete  sectional 
views  show  not  only  the  parts  cut  by  this  assumed 
plane,  but  also  any  other  parts  of  the  object  which  may 
be  seen  beyond.  In  symmetrical  objects  a  line  of  cen- 
ters or  other  line  of  symmetry  is  usually  chosen  through 
which  to  imagine  an  assumed  plane  has  been  passed. 
To  indicate  on  the  drawing  the  space  representing  this 
surface  (the  surface  produced  by  the  passing  of  this 
assumed  plane  through  the  object)  is  filled  with  uni- 
formly spaced  diagonal  lines.  Figs.  51  and  52.  This 
is  called  cross-hatching.  Different  pieces  of  material 
appearing  in  the  same  section  are  indicated  by  the  lines 


READING  WORKING  DRAWINGS  55 

running  in  different  directions.  Different  materials  are 
indicated  by  using  different  kinds  or  grouping  of  lines. 
An  incomplete  section  shows  the  objects  partly  in  full 
elevation,  and  partly  in  sectional  elevation.  Such 
drawings  are  also  called  broken  drawings.  Long, 
symmetrical  parts,  as  a  piece  of  shafting,  may  be  shown 
by  making  drawings  of  the  ends  close  together  with 
the  middle  portion  broken  out.  These  are  also  called 
broken  drawings,  and  are  used  to  save  space  or  to 
represent  a  long  piece  on  a  small  sheet. 

Various  arrangements  of  views  on  a  drawing  are 
possible,  each  of  which  may  be  equally  effective  in 
conveying  the  necessary  information.  Attempts  have 
been  made  to  establish  uniformity  of  practice  in  this 
respect,  without  effect,  for  the  reason  that  such  a  vast 
variety  of  forms  are  encountered,  and  difficulties  of 
execution  are  met  in  practical  work,  that  in  general  it 
is  not  possible  to  follow  any  cut-and-dried  rules.  When 
making  drawings  for  use  in  engineering  construction, 
especially  for  workshop  use,  that  draftsman  is  the  best 
one  who  can  convey  the  necessary  information  with  the 
least  expenditure  of  time  and  labor  spent  in  making  the 
drawing,  consistent  with  neatness  of  execution  and 
accuracy  of  dimensions. 

A  good  general  method  of  procedure  in  reading  a 
working  drawing  is  as  follows:  First,  ignore  for  the 
time  being  the  dimensions  and  dimension  lines  entirely 
until  an  idea  is  obtained  and  fixed  in  the  mind  of  the 
general  shape  of  the  object.  Second,  referring  to  the 
several  views,  notice  if  its  outline  is  to  be  a  cylinder, 
a  cube,  a  cone,  etc.,  or  a  combination  of  several  of  these 
elementary  forms.  This  being  clearly  impressed  on 


56 


WOOD  PATTERN-MAKING 


the  mind,  observe  how  it  is  modified  by  details,  and, 
always  referring  to  the  several  views,  determine 
whether  they  project  from  the  main  body,  or  are  re- 
cesses or  holes.  Finally  form  an  idea  of  the  relative 


FIG.  50. 

sizes  of  the  component  parts  by  referring  to  the  dimen- 
sions. Pay  strict  regard  to  all  conventional  represen- 
tations that  have  been  used. 

In  Fig.  50  is  shown  how  the  views  are  usually  ar- 
ranged when  three  views  of  an  object  are  given.  This 
arrangement  may  be  modified  when  some  other  will 
better  convey  the  meaning.  If  still  another  view  was 
thought  necessary  to  represent  the  object  as  it  would 


READING  WORKING  DRAWINGS 


57 


58 


WOOD  PATTERN-MAKING 


appear  when  looking  at  its  left  side  it  would  be  located 
at  the  left  of  the  front  view;  this  would  be  called 
the  left  side  view.  In  the  drawing,  A  is  the  plan  or 
top  view,  B  is  the  front  view,  and  C  is  the  right  side 
view.  These  names  are  purely  arbitrary,  and  any  side 
of  the  object  may  be  assumed  as  the  front  view,  except 


FIG.  52. 

when  the  object  has  a  natural  base,  as  a  table,  or  a 
machine,  etc.  Then  the  plan  is  a  drawing  of  the  top 
side  of  the  machine  as  it  stands  in  its  normal  position, 
that  is,  on  its  natural  base. 

One  good  way  of  determining  the  shape  of  an  object 
from  a  drawing  is  to  imagine  the  paper  on  which  the 
drawing  is  made  to  be  bent  on  a  line  somewhere  be- 
tween two  of  the  views  until  the  surfaces  are  perpen- 
dicular to  each  other,  or  actually  to  bend  the  paper  with 
the  drawing  on  it  in  this  manner;  then  imagine  some 
object  which  if  projected  on  the  two  planes  would  give 
outlines  like  the  ones  shown  on  the  drawing,  treating 
sectional  views  in  the  same  manner  as  full  views. 

Fig.  51  is  a  working  drawing  of  the  headstock  of  a 
lathe.  It  illustrates  several  of  the  conventions  pre- 
viously mentioned.  One  of  these  is  the  arrangement 
of  the  views. 


READING  WORKING  DRAWINGS  59 

What  is  known  as  a  broken  drawing  is  also  illus- 
trated in  Fig.  51  at  D  and  D.  In  this  case  one-half  of 
the  object  is  supposed  to  be  broken  away,  and  a  view 
given  as  the  object  appears  at  that  point  after  its  re- 
moval ;  this  makes  it  easily  understood  as  to  the  desired 
shape.  Another  convention  illustrated  is  the  method 
of  indicating  which  surfaces  are  to  be  machined.  It  is 
by  the  use  of  the  letter  F,  placed  on  or  near  the  surface 
to  be  machined  or  finished.  One  method  (broken  lines) 
of  indicating  the  location  and  size  of  tapped  holes  for 
the  reception  of  bolts  is  also  shown  in  the  center  of 
each  bearing.  Fig.  52  shows  one  way  of  representing 
simple  circular  objects  that  is  used  quite  frequently  in 
machine  drawings.  The  sectional  view  is  a  complete 
section. 


CHAPTER  IV 
PATTERN  TURNING 

The  term  wood-turning  is  generally  understood  to 
mean  the  making  or  forming  of  any  circular  form  re- 
quired of  wood,  while  revolving  at  a  high  rate  of  speed 
in  some  form  of  lathe.  Wood-turning  is  done  in  two 
distinct  ways;  first,  along  or  parallel  with  the  grain; 


FIG.  53. 


and  second,  across  the  grain,  or,  as  it  is  sometimes 
called,  plankwise.  Wood-turning  may  be  divided  into 
two  kinds,  cabinet  turning,  by  which  balusters  and  other 
decorative  articles  are  produced ;  and  pattern  turning, 
a  method  used  by  pattern-makers,  by  which  the 
many  circular  forms  required  in  that  trade  are  made. 
The  same  tools  are  used  on  both  kinds  of  turning,  but 

60 


PATTERN  TURNING  t>l 

the  processes  are,  in  some  respects,  quite  different.  The 
cabinet  turner  is  more  concerned  as  to  the  beauty  of 
outline  and  finish  than  with  exact  size,  and  uses  methods 
that  will  accomplish  these  results.  The  pattern  turner, 
on  the  other  hand,  must  have  exactness  in  size,  the 
finish  being  a  secondary  matter.  This  being  the  case, 
whereas  the  cabinet  turner  actually  cuts  the  fibres  of 
the  wood,  the  pattern  turner  uses  what  is  called  a  scrap- 
ing cut  for  most  of  his  work. 


FIG.  54. 

A  common  form  of  turner's  lathe  is  shown  by  Fig.  53. 
In  the  figure,  A  is  the  bed,  B  is  the  head-stock,  C  is  the 
tail-stock,  D  is  the  step-cone  pulley  on  which  the  belt 
runs  that  drives  it  and  the  spindle  G,  and  with  it  the 
driving  or  fork  center,  which  in  turn  drives  the  work. 
The  fork  center  is  driven  into  a  tapered  hole  in  the 
spindle,  and  is  held  by  friction  only.  In  the  tail-stock 
is  the  back  center,  H.  At  F  is  the  tool  or  hand  rest. 
E  is  the  tool-rest  post. 

Fig.  54  shows  an  enlarged  view  of  the  most  common 
form  of  fork  chuck.  The  fork  chuck  at  the  left  hand, 
and  the  back  center  at  the  right,  make  up  the  common 
appliance  for  holding  work  in  the  lathe,  when  the  turn- 
ing is  to  be  done  lengthwise  or  parallel  with  the  grain. 
For  turning  plankwise  or  across  the  grain,  there  are 
several  kinds  of  chucks  employed,  the  simplest  being 
the  screw  chucks,  shown  at  Fig.  55,  in  two  forms.  A 


02 


WOOD  PATTERN-MAKING 


face-plate  is  shown  in  the  center  of  Figs.  139  and  140. 
For  small  work,  a  chuck  may  be  simply  a  disk  of  wood. 
Each  chuck  must  have  a  face-plate  fastened  to  it  dur- 
ing its  use.  There  are  several  different  ways  of  fasten- 
ing work  to  these  chucks,  generally  determined  by  its 


FIG.  56. 


FIG.  55. 


size  and  shape.  It  may  be  fastened  with  screws  or  nails, 
it  may  be  glued  directly  to  the  chuck,  and  it  may  be 
glued  to  paper  already  glued  to  the  chuck.  When  this 
last  way  is  used,  the  work  may  be  taken  off  without 
damaging  it,  because  the  paper  will  split.  When  it  is 
glued  directly  to  the  chuck  it  will  have  to  be  cut  off, 
so  this  way  is  not  usually  employed  except  for  patterns 
of  thin  cross  section,  such  as  pulley  rims,  that  can  be 
easily  cut  through.  Besides  these  plain  chucks,  several 
other  forms  are  in  use  for  special  work,  one  of  which 
is  represented  by  Fig.  56,  and  is  called  a  cup  chuck. 
One  of  its  uses  is  to  hold  a  sphere  in  the  lathe  while  it 
is  being  given  the  finishing  touches. 


PATTERN  TURNING  63 

Not  many  different  forms  of  tools  are  required  for 
pattern  turning,  but  quite  a  number  of  different  sizes 
of  the  same  form  are  needed.  The  first  to  be  noticed  is 
the  turner's  gouge,  shown  in  Fig.  57,  and  the  skew,  or 
turning  chisel,  illustrated  in  Fig.  58.  These  two,  in 
their  different  sizes  are  the  only  tools  used  by  the  turner 
for  cutting  the  fiber  of  the  wood.  All  the  others  are 


FIG.  57. 


FIG.  58. 

really  scraping  tools,  and  do  not  actually  cut.  The  other 
tools  most  used  for  pattern  turning  are  illustrated  by 
Fig.  59.  At  A  is  shown  a  pair  of  the  ordinary  scrapers, 
the  tool  most  used  on  flat  and  convex  surfaces.  At  B 
is  shown  the  round-nosed  scraper,  used  for  concave 
surfaces ;  several  sizes  of  this  are  needed  for  a  medium 
range  of  work.  At  C  the  ordinary  parting  tool  is  shown. 
This  is  a  very  useful  tool  for  working  wood  plankwise ; 
its  special  form  gives  clearance  in  whatever  position  it 
may  cut  the  wood.  The  tool  shown  at  D  is  also  a  very 
good  tool  for  turning  wood  across  the  grain,  especially 
if  a  large  amount  of  wood  is  to  be  removed.  This  it  will 


64 


WOOD  PATTERN-MAKING 


do  rapidly  and  easily.  It  is  called  a  diamond-point  part- 
ing tool.  Fig.  60  shows  a  straight  scraper,  which  is 
very  useful  for  finishing  large  straight  surfaces.  It  is 
made  from  a  firmer  chisel  that  is  worn  too  short  for  its 
original  use.  Indeed,  worn-out  chisels  of  this  type 
make  first-class  turner's  scrapers.  All  the  scraping 


A 


B 
FIG.  59. 


tools,  except  those  shown  at  A  and  D,  may  be  made  of 
these  and  will  serve  their  purpose  admirably.  The  two 
noted  above  are  sometimes  needed  longer  than  the 
others,  and  are  better  if  made  of  heavier  stock. 

The  art  of  turning  can  be  learned  by  the  student  only 
in  the  same  way  that  any  other  mechanical  trade  or 
craft  is  learned,  i.  e.,  by  actually  doing  the  work  and 
performing  the  operations  involved  in  the  practice  of 
that  art.  This  being  the  case,  only  a  few  simple  direc- 
tions will  be  given  here.  These  directions  will  be  given 
by  explaining  the  operations  that  must  be  performed  in 
turning  a  cylinder.  The  first  thing  to  be  done  is  to  saw 
out  the  stock  square,  with  the  sides  about  one-eighth 
inch  larger  than  the  diameter  of  the  proposed  cylinder. 
Next  make  a  center  mark  on  each  end  by  drawing 
diagonal  lines  across  it ;  at  these  points  the  lathe  centers 


PATTERN  TURNING  65 

are  to  enter.  To  set  the  work  in  the  lathe,  place  one 
end  against  the  driving  center,  or  head  center,  and  with 
a  hammer  or  mallet  strike  the  other  end  until  the  chuck 
has  entered  the  wood  far  enough  to  revolve  the  wood 
against  the  tools  ;  now  while  holding  the  right-hand  end 
in  the  left  hand,  slide  up  the  tail-stock  with  the  right 
hand  until  its  center  touches  the  wood,  and  clamp  it  to 
the  bed.  With  the  handle  or  hand-wheel  connected 
with  the  tail  center,  push  the  center  into  the  right-hand 


FIG.  60. 

end  far  enough  to  make  it  secure.  Adjust  the  tool  rest 
so  it  will  just  clear  the  corner  of  the  piece  when  revolv- 
ing, and  about  a  half  inch  above  the  center  of  the  lathe. 
It  is  a  good  plan,  before  applying  the  power,  to  give 
the  belt  a  pull  with  the  hand  to  ensure  that  everything 
is  clear. 

The  gouge  is  the  first  tool  to  be  used  on  this  kind  of 
turning;  the  cutting  done  by  it  at  this  stage  of  the 
work  is  termed  the  roughing  cut.  The  gouge  is  so  held 
that  a  center  line  through  the  tool  will  be  perpendicular 
to  the  axis  of  the  work.  The  bevel  of  the  cutting  wedge 
should  be  held  tangent  to  the  proposed  cylinder,  and 
rolled  on  its  side  as  indicated  by  Fig.  61  at  A.  The 
direction  in  which  the  tool  is  moving  is  indicated  by 
the  arrow  in  each  case,  In  this  position  the  angle  of  the 
cut  will  be  about  25°  to  30°  with  the  axis  of  the  cylinder, 
which  is  the  best  for  this  kind  of  turning.  The  gouge  is 


66  WOOD  PATTERN-MAKING 

used  by  good  turners  for  doing  a  very  large  proportion 

of  the  work  on  plain  cylindrical  and  concave  surfaces. 

Plain  cylindrical  and  convex  surfaces  are   finished 

with  the  turning  or  skew  chisel,  the  only  other  cutting 


FIG.  61. 


tool  used  by  turners.  Its  use  requires  a  great  deal  of 
skill  on  the  part  of  the  operator.  On  account  of  its 
shape  is  has  a  great  tendency  to  rip  or  tear  into  the 


FIG.  62. 


work  with  its  long  corner.  One  reason  for  its  so  doing 
lies  in  the  fact  that  it  cannot  be  laid  flat  on  the  tool  rest, 
but  must  be  supported  as  shown  in  Fig.  62,  and  at  the 
left  in  Fig.  63.  This  being  the  case,  the  keeping  of  the 
edge  of  the  chisel  in  its  proper  position  and  angle  with 


PATTERN  TURNING 


67 


the  work  depends  entirely  on  the  skill  of  the  workman. 
This  skill  cannot  be  imparted,  but  some  suggestions 
can  be  given  that  will  aid  the  student  in  acquiring  it. 
Do  not  let  the  chisel  cut  above  the  central  point  of  the 
length  of  the  cutting  edge,  that  is  at  D,  in  Fig.  62. 
Retain  a  firm  grip  on  the  handle  with  the  right  hand. 


FIG.  63. 


The  bevel  of  the  skew,  like  that  of  the  gouge,  should 
be  laid  on  the  cylinder  exactly  tangent,  and  held  so 
that  the  handle  is  perpendicular  to  the  axis  of  the  cylin- 
der. As  one  corner  only  of  the  chisel  touches  the  rest, 
it  is  very  difficult  to  keep  it  in  its  correct  position.  If 
the  bevel  is  exactly  tangent,  it  will  not  cut ;  so  it  must 
be  tipped  enough  to  be  tangent  to  a  circle  slightly 
smaller  than  the  one  already  cut.  This  is  best  done  by 
simply  rolling  the  chisel  with  the  hand  until  it  cuts  a 
shaving  of  the  desired  thickness.  As  a  general  rule, 
the  cylinder  should  be  cut  almost  to  size  with  the  gouge, 
leaving  only  a  shaving  or  two  to  be  removed  by  the 
chisel. 

Pattern-makers  do  almost  all  this  finishing  with  a 
scraper  like  the  one  shown  in  Fig.  60.  The  position  of 
this  tool  for  scraping  plain  cylindrical  surfaces  is,  as 


68  WOOD  PATTERN-MAKING 

shown  in  Fig.  64,  exactly  on  the  diameter  of  the  cylinder. 
The  cutting  of  shoulders  like  those  in  Fig.  63,  also  the 
squaring  of  the  ends  of  the  cylinder,  is  done  with  a 
skew  chisel.  The  chisel  is  held  as  there  shown,  that  is, 
at  a  slightly  larger  angle  than  the  one  at  which  it  is 


FIG.  64. 


sharpened;  so  no  part  of  the  edge,  except  the  extreme 
point,  touches  the  wood.  The  ends  of  nearly  all  plain 
cylindrical  patterns  have  to  be  made  convex.  To  make 
them  so,  the  chisel  may  be  held  with  the  center  line  of 
its  length  perpendicular  with  the  axis  of  the  cylinder, 
while  at  the  same  time  the  edge  of  the  chisel  is  perpen- 
dicular. For  making  other  forms  in  the  lathe,  the  tools 
shown  in  Fig.  59  are  used.  These  are  all  scraping  tools. 


SHARPENING  LATHE  TOOLS 

The  cutting  wedges  of  the  turning  gouge  and  the 
turning  chisel  are  sharpened  in  the  same  way  as  other 
cutting  wedges.  The  wedges  for  soft  wood,  however, 
should  be  more  acute  than  the  bench  chisel  for  general 
work.  The  wedge  of  turning  chisels  for  use  in  soft 
wood  may  be  ground  to  an  angle  of  20°,  and  must  be 
kept  very  keen  if  good  work  is  to  be  done.  The  side 
angle  for  the  skew  chisel  should  be  about  70°.  The 
roughing  gouge  should  have  a  wedge  of  30°.  The 
scraping  tools  should  have  wedges  of  about  45°,  and 
be  ground  on  one  side  only,  as  shown  in  Fig.  64.  As 
the  cutting  edge  of  the  scraping  wedge  is  on  the  side 
instead  of  on  the  end  as  in  the  cutting  wedge,  it  requires 
a  different  treatment  to  secure  the  best  results.  After 
sharpening  the  chisel  in  the  usual  way,  place  it  on  the 
oilstone  on  its  bevel,  and,  while  holding  it  in  that  posi- 
tion, give  it  two  or  three  strokes  parallel  with  the  back. 
This  will  give  a  continuous  wire  edge,  which  is  just 
what  is  needed.  Pushing  the  chisel  back  and  forth  in 
the  usual  way  also  produces  a  wire  edge,  but  it  is  a 
serrated  one,  and  therefore  is  quickly  dulled. 


69 


TOOLS  FOR  MEASURING  TURNED  WORK 

The  special  tools  for  measuring  turned  work  are 
shown  at  Figs.  65  and  66.  The  former  is  the  outside 
caliper,  the  latter  the  inside  caliper.  The  outside  caliper 
io  used  for  measuring  the  outside  of  round  or  cylindrical 
work,  the  inside  caliper  for  measuring  holes  and  cavities 
either  cylindrical  or  of  other  forms.  The  outside  caliper 
may  be  used  when  the  work  is  revolving,  provided  it  is 


FIG.  65. 


FIG.  66. 


very  nearly  cylindrical.  The  inside  caliper  should  not 
be  applied  to  work  that  is  revolving,  as  it  is  likely  to  be 
caught  by  the  wood  and  jerked  out  of  the  hand.  The 
common  two-foot  rule  is  used  for  measuring  along  a 
cylinder  when  the  caliper  would  be  unhandy.  When  a 
number  of  pieces,  balusters  for  instance,  are  to  be  made 
alike,  a  special  measuring  device  is  usually  made  use  of 
by  turners.  It  consists  of  a  light  stick  of  wood  with 
sharpened  wire  brads  driven  into  it  at  certain  points 
along  its  length,  where  the  deeper  cuts  are  to  be  made. 


70 


PATTERN. TURNING  71 

After  the  piece  is  turned  down  roughly  to  size,  this 
scriber,  as  it  is  called,  is  laid  on  the  tool  rest  in  such  a 
way  that  the  sharpened  nails  will  just  touch  the  cylinder 
as  it  revolves,  thus  making  a  line  around  it  where  it 
is  to  be  cut.  This,  of  course,  saves  time,  for  the  reason 
that  the  lines  are  all  made  at  once,  and  the  distances 
between  them  are  measured  at  the  same  time  for  all 
the  parts.  It  is  not  often,  however,  that  the  pattern- 
maker has  any  use  for  this  device,  as  his  work  is  seldom 
duplicated. 


CHAPTER  V 
INTRODUCTION  TO  PATTERN-MAKING 

A  pattern  may  be  defined  as  a  model  about  which  is 
to  be  formed  a  sand  mold,  in  which  a  casting  is  to  be 
made.  It  is  usually  of  wood  or  metal,  and  often  con- 
structed in  several  parts  so  as  to  facilitate  removal  from 
the  mold.  In  the  foundry  and  machinery  business  the 
word  pattern  is  understood  to  mean  any  form  or  device 
by  the  use  of  which  a  mold  may  be  made.  Pattern- 
making  differs  from  all  other  woodwork  in  several  ways. 
The  product  of  the  pattern  shop  becomes  a  part  of  the 
working  outfit  of  another  workman,  viz.,  the  molder. 
The  joiner,  in  making  a  door,  makes  it  just  the  size 
required  by  the  drawing  or  specifications ;  the  cabinet- 
maker does  the  same  when  called  upon  to  make  a  table 
or  other  piece  of  furniture ;  the  carpenter  also  follows 
this  same  idea  when  building  a  bridge.  In  all  these,  the 
ultimate  object  is  reached  when  the  work  is  complete. 
It  is  not  so,  however,  with  the  pattern-maker;  his 
product  is  only  one  step  in  arriving  at  the  desired  end, 
that  end  being  the  production  of  one  or  more  castings  in 
some  kind  of  metal.  Allowances  must  be  made  in  con- 
structing a  pattern,  that  do  not  have  to  be  considered 
in  other  woodwork ;  the  principal  of  these  allowances 
are  for  draft,  shrinkage  of  the  metal  of  the  casting,  and 
the  machining  of  the  casting  where  this  is  required.  A 
pattern-maker  must  be  a  good  woodworker,  and  able 
to  work  wood  to  accurate  dimensions,  both  on  the  bench 

72 


INTRODUCTION  TO  PATTERN-MAKING  73 

and  in  the  lathe,  as  pattern-making  consists  largely  of 
fitting,  joining,  and  making  circular  and  other  forms 
to  correct  size.  This  knowledge  and  ability  are  nec- 
essary to  the  pattern-maker,  because  a  large  majority 
of  patterns  are  made  of  wood.  The  pattern-maker 
must  also  know  something — and  the  more  the  better — 
of  the  practical  work  of  the  molder.  This  is  necessary 
in  order  that  he  may  be  able  to  produce  easily  molded 
patterns.  He  should  possess  a  good  practical  knowl- 
edge of  the  properties  of  metals,  as,  for  instance,  the 
contraction  or  shrinkage  that  these  undergo  in  passing 
from  the  molten  to  the  solid  state,  the  strength  of  cast 
metals,  and  their  relative  rate  of  cooling.  He  should 
also  thoroughly  understand  the  principles  of  ortho- 
graphic projection,  so  that,  if  it  becomes  necessary,  as 
is  frequently  the  case,  he  can  make  full-sized  working 
drawings  of  the  work  in  hand. 

The  production  of  ordinary  metal  castings,  such  as 
those  of  iron  or  brass,  involves  three  distinct  opera- 
tions : — First,  making  the  pattern ;  second,  from  this 
pattern  a  mold  is  made  in  sand  or  some  other  substance 
that  is  refractory  enough  to  withstand  the  action  of 
melted  metal ;  third,  the  metal  is  melted  and  poured 
into  this  mold.  Each  of  these  operations  require  espe- 
cial skill,  and  has  given  rise  to  a  special  trade,  although 
the  second  and  third,  called  respectively  molding  and 
founding,  are  often  performed  by  the  same  person. 
These  operations  are  sometimes  so  intricate,  and  admit 
of  so  much  variety,  that  the  above  statements  are  only 
true  in  the  main.  Nevertheless,  they  hold  good  in  gen- 
eral, and  in  consideration  of  this  subject  the  pattern- 
maker may  be  understood  to  be  a  woodworker,  the 


74  WOOD  PATTERN-MAKING 

molder  as  one  who  makes  the  mold,  and  the  founder  as 
the  one  who  has  charge  of  the  furnace  and  the  melting 
of  metals. 

In  the  first  of  these  operations,  that  of  the  pattern- 
maker, there  is  needed  a  fine  degree  of  skill  in  the  arts 
of  cabinet-making  and  wood-turning.  Moreover,  the 
two  trades,  the  molder's  and  pattern-maker's,  are  so 
intimately  connected  that  it  is  almost  impossible  to 
describe  one  without  frequent  reference  to  the  other, 
and  as  a  matter  of  fact  there  is  almost  as  much  to  be 
learned  of  pattern-making  in  the  foundry  as  in  the  pat- 
tern shop.  So  intimately  connected  are  the  operations 
of  pattern-making  and  molding,  that  one  of  the  chief 
qualifications  of  a  good  pattern-maker  is  the  ability 
to  form  a  rapid  and  reliable  judgment  as  to  the  best 
of  the  several  ways  of  molding  a  given  pattern.  As 
there  is  usually  more  than  one  way,  it  is  advisable 
that  the  pattern-maker,  if  in  any  doubt,  confer  with 
the  molder  as  to  his  preference  in  the  matter ;  as  the 
molder  is  responsible  for  the  production  of  the  casting, 
he  should  have  the  pattern  as  he  wants  it.  As  pattern- 
making,  therefore,  is  to  be  regarded  primarily  from  the 
molder's  standpoint,  and  not  from  that  of  the  wood- 
worker, the  following  matters  are  of  first  importance  : — 

(1)  Patterns,  when  in  use,  being  entirely  enclosed 
in  matrices  of  sand,  provision  must  be  made  for  pulling 
them  out ;  this  involves  draft,  or  taper,  which   is  a 
thinning  down  of  certain  parts,  division  into  sections, 
and  provision  for  loosening  by  rapping. 

(2)  Molding  sand  is  always  used  damp,  and  pat- 
terns are  subject  to  rough  usage;  consequently  they 
must  be  made  so  as  to  resist  any  tendency  to  change 


INTRODUCTION  TO  PATTERN-MAKING  75 

their  form  and  size  from  the  absorption  of  moisture 
from  the  damp  sand,  and  they  must  be  strongly  con- 
structed. 

(3)  Most  metals  shrink  or  contract  in  passing  from 
the  molten  to  the  solid  state ;  therefore,  patterns  must 
be  made  larger  than  the  required  casting  to  allow  for 
this. 

(4)  Patterns  may  be  entire  or  complete,  exactly  like 
the  castings  wanted ;  if,  however,  there  are  cavities  to 
be  formed  in  the  casting,  these  hollow  places  will  be 
represented  by  core  prints.     Moreover,  the  part  the 
pattern-maker  has  to  do  with  getting  out  a  given  cast- 
ing may  be  the  preparation  of  a  sectional  part  or  parts 
of  a  pattern  from  which  only  one  part  of  the  mold  is 
made ;  the  other  part  is  made  with  a  sweep,  the  boards 
for  which  are  also  prepared  by  the  pattern-maker. 

(5)  The  practice  of  pattern-making  is  largely  gov- 
erned by  the  requirements  of  the  engineer;  these  re- 
quirements are  that  patterns  must  correspond  to  draw- 
ings  in  all   dimensions,  that  all   centers  be   correctly 
located,  and  that  all  necessary  allowances  be  made  both 
for  machining  and  for  the  shrinkage  of  the  metal  of  the 
casting. 

It  will  thus  be  seen  that  the  pattern-maker  has  very 
little  in  common  with  the  carpenter,  or  indeed,  with  any 
other  woodworker,  except  for  the  fact  that  he  uses  the 
same  tools  and  processes.  To  understand,  then,  the 
fundamental  principles  of  pattern-making,  it  is  neces- 
sary to  master  the  principles  of  molding,  and  much  of 
its  details  as  well,  and  to  have  a  good  working  knowl- 
edge of  modern  machine  shop  practice.  It  is  well  to 
remember  also  that  mere  outside  polish  or  finish  on  a 


76  WOOD  PATTERN-MAKING 

pattern  does  not  count  for  much  if  such  matters  as 
correct  construction  and  others  already  spoken  of,  are 
neglected. 

In  many  trades,  to  become  an  expert  in  handling 
tools,  is  the  most  necessary  requirement ;  but  this  is 
not  the  case  in  pattern-making,  there  being  something 
far  more  important  than  cutting  wood.  In  the  con- 
struction of  many  patterns  it  is  not  so  much  a  question 
of  workmanship,  as  of  knowledge.  Certain  patterns, 
for  example,  are  very  difficult  to  design,  but  after  they 
are  once  made,  they  can  be  duplicated  by  any  good 
woodworker.  In  fact,  it  often  requires  but  little  skill 
to  construct  the  necessary  core  boxes,  etc.,  that  may 
be  required  to  produce  certain  castings ;  on  the  other 
hand,  there  is  much  pattern-making  that  calls  for  fine 
workmanship.  In  any  event,  pattern-making  is  not 
merely  cutting  wood. 

From  what  has  been  said,  then,  it  will  readily  be 
appreciated  that  pattern-making  is  an  important  and 
responsible  trade.  For  while  the  duty  belongs  to  the 
draughtsman  of  preparing  the  design,  yet  the  pattern- 
maker must  be  able  so  to  interpret  that  design  as  to  get 
the  idea  the  draughtsman  intended  to  convey.  More- 
over, he  must  look  forward  to  the  requirements  of  the 
molder;  consequently,  from  the  drawing  alone  he  must 
be  able  to  imagine  the  completed  casting,  and  build  a 
pattern  that  will  produce  it.  As  the  medium  by  which 
the  designer's  ideas  are  put  into  the  tangible  form  of  a 
casting,  the  pattern-maker  then  has  a  two-fold  responsi- 
bility. Another  fact  that  adds  to  this  is  that  there  are 
so  many  different  ways  of  molding.  This  gives  a  great 
field  of  study  for  the  pattern-maker. 


CHAPTER  VI 
MOLDING 

A  pattern-maker  should  know  something  about  the 
operations  of  the  molder,  so  that  he  can  make  a  partic- 
ular pattern  of  such  a  shape  that  it  can  be  molded  in  the 
easiest  way  possible.  This  being  the  case,  it  is  neces- 
sary to  explain  some  of  these  operations.  The  form  of 
pattern  shown  in  Fig.  68  is  what  is  known  as  a  parted 
pattern.  The  molding  operations  that  this  form  in- 


FIG.  68. 

volves  are  generally  few  and  simple.  As  will  be  seen, 
the  pattern  is  made  in  two  parts,  the  parting  or 
joint  being  along  the  axis  of  the  cylinder.  It  is  made 
in  this  way  for  the  convenience  of  the  molder.  These 
two  parts  are  held  sideways  in  relation  to  each  other 
by  what  are  called  pattern  pins,  represented  by  dotted 
lines,  c  and  d.  Parts  marked  A  and  B  are  core  prints, 
and  will  not  appear  on  the  casting. 

The  appliance  used  by  the  molder  in  which  to  make 
the  mold  is  called  a  flask,  and  is  illustrated  by  Fig.  69. 
The  upper  part,  A,  is  called  the  cope,  the  lower  part,  B, 
the  nowel  or  drag;  C  is  the  bottom  board;  D,  the  cope 

77 


78  WOOD  PATTERN-MAKING 

bars;  E,  the  guide  pins.  Each  flask  is  composed  of  at 
least  these  three  main  parts,  viz.,  cope,  nowel,  and  bot- 
tom board.  Sometimes  another  part  is  introduced  be- 
tween the  nowel  and  cope,  called  the  cheek,  or  middle 
part.  This  is  necessary  when  the  casting  is  of  such 
shape  that  its  pattern  cannot  be  taken  from  the  mold 


FIG.  69. 

with  the  one  parting  obtained  by  the  use  of  cope  and 
nowel  alone — that  is,  with  the  simple  form  of  flask 
shown  by  Fig.  69.  In  addition  to  these  parts  a  molding 
board  is  needed,  which  may  be  just  like  the  bottom 
board.  Only  one  molding  board  is  required  by  one 
workman  for  any  number  of  flasks  of  the  same  size. 

The  words  top  and  bottom  will  be  frequently  used  in 
writing  of  this  flask.  They  refer  to  the  flask  when 
standing  in  what  may  be  called  its  normal  position — 
that  is,  as  it  stands  when  the  mold  is  ready  for  the 
melted  metal  to  be  poured  in.  The  relative  position  of 
these  two  parts  is  that  the  cope  is  always  on  top,  the 


MOLDING  79 

nowel  at  the  bottom.  Each  part  is  a  box  having  neither 
top  nor  bottom,  the  sides  generally  being  about  5  or  6 
inches  high,  and  rough  inside. 

In  order  that,  after  being  separated,  these  may  be 
put  together  again  in  the  same  relative  position,  they 
are  provided  with  guide  pins,  E,  Fig.  69,  the  pins  proper 
being  on  the  cope,  and  the  lugs  into  which  they  fit  being 
on  the  nowel.  The  cope  is  also  provided  with  some 
form  of  handles.  In  Fig.  69  one  of  these  is  shown  above 
E,  being  in  this  case  a  strip  of  wood  about  I  inch  square 
nailed  across  the  end,  directly  above  the  guide  pins. 
These  handles  are  provided  for  the  purpose  of  lifting 
the  cope  from  the  nowel  at  any  time  it  becomes  neces- 
sary to  do  so  during  the  process  of  molding. 

There  are  also  cross  bars  fastened  across  the  cope, 
D,  Fig.  69,  to  assist  in  retaining  the  sand,  which  is  held 
in  place  by  friction  only,  the  cope  from  necessity  having 
no  bottom.  In  all  other  respects  cope  and  nowel  are 
alike,  except  that  in  some  cases  one  may  be  deeper  than 
the  other. 

In  using  this  appliance  the  molder  first  places  the 
molding  board  on  the  sand  floor  of  the  foundry  in  an 
approximately  level  position,  and  so  it  will  not  rock. 
He  then  places  the  half  of  the  pattern  that  is  without 
pins  on  its  flat  side  in  the  center  of  the  molding  board. 
The  nowel,  or  drag,  which  is  the  lower  half  of  the 
flask,  is  next  placed  on  this  board,  bottom  side  up,  with 
the  half  pattern  in  the  middle  of  it.  Next  he  sifts  mold- 
ing sand  on  to  this  board  until  the  half  pattern  is  cov- 
ered to  a  depth  of  an  inch  or  more.  He  now  shovels 
in  sand  until  the  nowel  is  filled  and  heaped  up ;  then, 
with  an  implement  called  a  rammer,  he  rams  it  down 


80  WOOD  PATTERN-MAKING 

solid.  The  sand  is  now  struck  off  even  with  the  bottom 
of  the  nowel,  some  loose  sand  thrown  on,  and  the  bot- 
tom board  placed  on  and  rubbed  around  so  as  to  make 
a  solid  bed  for  the  body  of  sand  in  the  nowel.  Clamps 
are  now  put  on  so  as  to  hold  all  together ;  the  whole 
is  turned  over,  the  clamps  removed,  and  the  molding 
board  lifted  off.  This  completes  one-half  of  the  mold, 
or,  as  the  molder  expresses  it,  "the  nowel  has  been 
rammed  up  and  turned  over."  He  now  sleeks  the  sur- 
face with  his  trowel  until  it  is  even  with  the  flat  surface 
of  the  half  pattern,  which  is  exposed  to  view,  sur- 
rounded by  sand.  He  next  scatters  on  some  parting 
sand,  which  is  a  very  dry  sand,  usually  burnt  sand  that 
has  been  cleaned  from  castings  already  made.  The 
purpose  of  this  is  to  prevent  t;he  next  body  of  sand 
from  sticking.  The  other  half  of  the  pattern  is  now 
laid  on,  its  position  being  determined  by.  the  pins 
already  spoken  of,  and  the  corresponding  holes  in  the 
other  half  of  the  pattern.  The  sprue  pin  or  stick  is  now 
set  up  on  the  sand  or  parting  just  finished.  This  pin 
is  a  piece  of  wood,  whose  shape  is  the  frustrum  of  a 
cone  about  10  inches  long;  its  purpose  is  to  make  a 
hole  through  the  cope  sand  into  which  the  melted  metal 
may  be  poured.  Sand  is  put  into  the  cope  in  the  same 
way  as  was  done  with  the  nowel ;  it  is  struck  off  even 
with  the  top,  the  sprue  pin  is  pulled  out,  and  the  whole 
surface  brushed  over  so  as  to  remove  all  loose  sand. 
The  cope  is  lifted  off  carefully,  and  set  to  one  side. 
Both  halves  of  the  mold  now  appear  exactly  alike, 
except  that  the  cope  has  the  sprue  hole  running 
through  it.  ' 

The  two  halves  of  the  pattern  must  now  be  drawn 


MOLDING  81 

or  pulled  out.  This  the  molder  proceeds  to  do  in  the 
following  manner:  If  the  pattern  is  provided  with 
lifting  plates,  as  all  standard  patterns  should  be,  he 
introduces  the  end  of  the  lifting-screw  into  the  hole 
provided  for  it  in  the  lifting  plate,  and  turns  it  in  so 
that  it  is  solid.  If  there  are  no  lifting  plates,  he  drives 
what  he  calls  a  draw-spike  into  one  of  the  halves.  Then, 
with  a  mallet,  a  small  hammer,  or  perhaps  a  sprue  pin, 
he  raps  on  all  sides  of  the  lifting-screw  or  draw-spike, 
so  as  to  loosen  the  pattern.  This  operation,  called 
rapping  the  pattern,  enlarges  the  mold  so  that  the 
pattern  may  be  pulled  or  drawn  out.  This  he  now 
does,  very  slowly  and  carefully,  gently  rapping  the 
pattern  until  it  is  entirely  free  from  the  mold.  This 
is  done  to  both  halves.  A  channel  is  now  cut  in  the 
sand  of  the  nowel  from  the  spot  on  the  parting  where 
the  sprue  pin  was  set,  to  the  mold  or  cavity  left  by 
removing  the  pattern.  Thus  is  provided  a  passage 
through  which  the  melted  metal  may  run  and  fill  the 
mold.  This  channel  is  called  the  gate.  The  mold  is  now 
ready  to  have  the  core  set  in.  After  the  core  is  set,  the 
cope  is  put  back  into  its  original  or  normal  position, 
which  is  determined  by  the  guide  pins  ;  the  whole  is  then 
clamped  together,  and  set  in  position  for  pouring.  As 
stated  at  the  beginning,  this  process  applies  only  to 
parted  patterns.  This  same  flask  may  be  used  in  sev- 
eral different  ways,  the  particular  way  being  deter- 
mined by  the  shape  and  size  of  the  pattern.  For 
some  shapes  of  patterns  it  is  necessary  to  use  three 
boxes  or  parts ;  this  is  usually  called  a  three-part  flask, 
thereby  meaning  that  the  mold  is  composed  of  three 
distinct  bodies  of  sand.  The  central  part  of  a  three- 


82  WOOD  PATTERN-MAKING 

part  flask  is  called  the  cheek.  The  cheek  has  on  it  a 
set  of  guide  pins  the  same  as  the  cope,  and  also  a  set 
of  lugs  like  those  on  the  nowel,  on  the  opposite  edge. 
It  is  made  in  this  way  so  that  any  cope  or  nowel  of  the 
same  size  may  be  used  with  it. 

These  simple  explanations  will  be  enough  to  give 
the  student  of  pattern-making  a  general  idea  as  to  the 
use  of  patterns  in  the  foundry.  Of  course  there  are 
many  details  to  be  observed  and  carried  out  in  the 
production  of  castings  that  are  not  mentioned  above, 
but  as  these  more  particularly  concern  the  molder 
than  the  pattern-maker,  they  will  not  be  noticed  here. 


CHAPTER  VII 
GENERAL  PRINCIPLES 

In  building  foundry  patterns  several  ideas  must  be 
kept  in  mind,  either  consciously  or  unconsciously. 
These  are  four  in  number,  or  (when  we  have  no  source 
of  information  as  to  what  is  wanted,  except  a  drawing 
of  the  required  casting),  there  may  be  five,  as  follows: 

(i)  What  may  be  called  the  designer's  idea;  (2) 
the  way  in  which  the  pattern  is  to  be  pulled  from  the 
sand;  (3)  the  draft,  or  taper,  which  is  a  thinning  down 
of  certain  parts  of  the  pattern  in  order  to  facilitate  its 
removal  from  the  mold  or  sand ;  (4)  the  shrinkage  of 
the  metal  of  the  proposed  casting,  while  passing  from 
the  molten  to  the  solid  state ;  and  (5)  the  machining 
or  finishing  of  the  casting  after  it  is  made  or  cast. 

An  experienced  pattern-maker  may  not  be  conscious 
that  he  has  in  mind  any  one  of  these  ideas,  because  he 
uses  them  so  frequently  that  he  does  so  without  think- 
ing especially  of  them  ;  in  other  words,  they  become 
second  nature  to  him.  It  is  these  last  four  ideas,  among 
others,  that  separate  this  trade  from  all  other  wood- 
working trades  and  connect  it  with  the  engineering 
profession,  for  there  is  not  one  of  them  that  has  even 
to  be  thought  of  by  those  working  at  any  other  of  the 
woodworking  trades.  Before  we  explain  these  ideas 
in  detail,  it  will  be  best  to  have  them  arranged  before 
the  mind  in  such  a  way  that  they  may  be  be  easily 
remembered,  and  in  the  order  of  their  use  and  import- 

83 


84  WOOD  PATTERN-MAKING 

ance.  For  convenience,  then,  we  will  put  them  in  a 
vertical  column,  thus  : — 

1.  Designer's  idea. 

2.  Way  to  be  drawn  from  the  mold. 

3.  Draft. 

4.  Shrinkage  of  metal. 

5.  Machining. 

Besides  these  five  ideas,  the  last  three  of  which  are 
called  allowances,  there  are  two  others  that  sometimes 
have  to  be  considered,  viz.,  for  shake  and  for  warp. 

The  first  two  of  these  five  ideas  are  purely  abstract. 
If  it  is  desired  to  make  a  pattern  from  a  drawing  only, 
that  is,  if  there  is  no  other  means  of  knowing  what  is 
wanted,  then  it  will  be  necessar)'  for  the  one  building  it 
to  form  as  nearly  as  possible  the  same  mental  picture 
that  the  designer  had  in  mind  when  making  the  draw- 
ing. This  may  be  called  the  designer's  idea,  and  to 
some  extent,  at  least,  must  be  realized  before  much  can 
be  done  towards  building  the  pattern.  After  having 
thus  formed  in  mind  the  general  shape  and  approximate 
size  of  the  required  pattern,  it  should  be  decided  which 
way  it  shall  be  drawn  from  the  mold.  This  must  be 
decided  before  very  much  can  be  done  towards  building 
the  pattern,  so  that  the  draft  may  be  made  in  the  right 
direction,  which  is  a  very  important  matter. 

The  other  three  points  that  were  mentioned  are 
sometimes  spoken  of  as  the  allowances  to  be  made  in 
pattern-making.  They  are  really  additions  made  to  the 
size  of  the  pattern  in  some  one  direction,  or,  as  in  the 
case  of  shrinkage,  in  all  directions.  The  first  of  these, 
and  in  some  respects  the  most  important,  is  what  is 
technically  termed  draft.  This  is  a  thinning  down  of 


GENERAL  PRINCIPLES 


85 


certain  parts  of  the  pattern ;  that  is,  the  vertical  sides 
of  the  pattern  are  tapered,  and  it  is  sometimes  spoken 
of  as  the  taper. 

The  amount  of  draft  to  be  allowed  is  governed  by 
the  case  in  hand,  some  patterns  requiring  more  than 
others.  The  usual  amount  is  l/%  inch  for  I  foot  in 
height;  this  is  generally  enough  for  small  and  compara- 
tively plain  work,  but  for  complicated  work  it  is  not 
enough.  No  hard-and-fast  rule,  however,  can  be  given 
for  this  allowance,  or  indeed  for  any  work  in  pattern- 


FIG.  70. 

making.  What  is  nearest  to  a  general  rule  may  be 
stated  thus :  Give  the  pattern  as  much  draft  up  to  /4 
inch  per  foot  in  height  as  will  not  interfere  with  the 
design.  Whatever  amount  is  allowed  should  be  added 
to  the  size  of  the  casting  as  given  in  the  drawing.  For 
small  and  plain  work  ^  inch  will  be  enough,  but  if  the 
pattern  is  at  all  complicated,  ^4  inch  will  not  be  too 
much.  Of  course,  the  requirements  of  the  molcler  have 
to  be  considered,  and  if  he  were  asked  about  it,  he 
would  always  say,  give  it  the  larger  amount.  To  make 
this  more  plain,  we  will  suppose  that  a  pattern  is 


86  WOOD  PATTERN-MAKING 

wanted  from  which  to  make  a  mold  for  the  casting 
represented  by  Fig.  70. 

Now,  applying  the  above  principle,  we  should  make 
the  top  longer  and  wider  than  the  size  given  by  Y4  inch, 
so  that  the  top  of  the  pattern  would  be  8*4  inches  long 
and  6*4  inches  wide.  This  addition,  or  allowance,  is 
shown  by  the  dotted  lines.  In  this  case  the  pattern 
would  be  drawn  out  of  the  mold  in  the  direction  of  the 
arrow.  In  practice  it  would  not  be  necessary  to  allow 
so  much  draft  on  as  plain  a  pattern  as  this,  but  we  use  it 
as  an  illustration  of  what  is  meant  by  the  term  draft. 
All  vertical  sides  of  the  pattern,  whatever  its  shape, 
must  have  some  taper  in  order  that  the  molder  may  get 
it  out  of  the  mold  without  breaking  the  mold.  If  no 
draft  is  allowed,  the  molder  has  to  rap  the  pattern  so 
much  that  the  mold  will  be  distorted  and  the  casting 
will  not  be  like  the  pattern. 

The  next  important  principle  to  be  observed,  espe- 
cially when  the  casting  is  required  to  be  exact  in  size, 
is  that  relating  to  shrinkage.  Whenever  this  word  is 
used  in  connection  with  pattern-making,  it  always 
means  the  shrinkage  or  contraction  of  the  metal  of 
which  the  casting  is  made.  An  iron,  brass,  or  steel 
casting  is  always  smaller  than  the  mold  in  which  it 
was  made,  and  this  is  true  also  of  castings  made  of  any 
of  the  other  metals  in  common  use.  This  is  due  to  the 
shrinkage  of  the  metal  when  cooling.  The  amount  of 
the  shrinkage  varies  in  the  different  metals,  and  also 
in  the  same  metal  under  varying  conditions.  Brass 
will  shrink  more  than  iron,  and  iron  that  is  very  hot 
when  it  is  poured  into  the  mold,  will  shrink  more  than 
iron  that  is  comparatively  cool  when  poured.  The 


GENERAL  PRINCIPLES  87 

size  and  the  shape  of  the  casting  also  have  much  to  do 
with  the  amount  of  shrinkage.  An  iron  that  will  shrink 
Y%  inch  to  the  foot  in  light  work,  will  shrink  only  i/io 
inch,  or  less,  in  large  work.  For  instance,  in  casting 
large  box  or  cylindrical-shaped  castings,  1/8  inch  per 
foot  is  usually  enough  to  allow  for  this  shrinkage  in 


the  diameter,  but  1/8  inch  will  not  be  too  much  in  the 
length.  The  reason  for  this  difference  is  due  to  the 
fact  that  the  castings  are  practically  unrestrained  in 
their  length,  and  are  comparatively  free  to  shrink  in 
this  direction,  while  in  the  diameter  they  are  restricted 
by  the  cores  and  internal  parts  of  the  mold.  The  amount 
of  allowance  usually  made  in  common  practice  is  1/8 
inch  per  foot,  measured  in  all  directions.  But  since 
the  coefficient  of  shrinkage  is  different  for  different 
metals,  this  is  only  approximate.  The  following  allow- 
ances for  the  different  metals  are  made  in  the  pattern 
when  it  is  surely  known  just  what  metal  the  casting 
is  to  be  made  of,  as,  of  course,  is  usually  the  case.  One 
good  way  to  remember  these  is  to  arrange  the  figures 
that  represent  these  amounts  in  a  group  like  Fig.  71. 


88  WOOD  PATTERN-MAKING 

For  iron,  then,  this  allowance  is  i/io  inch ;  for  brass, 
3/16  inch ;  aluminum,  1/4  inch,  and  for  steel,  1/4  inch ; 
the  general  amount,  which  is  in  the  center  of  the  group, 
is  1/8  inch.  It  must  not  be  understood  by  this  that 
these  metals  will  always,  and  under  all  conditions, 
shrink  just  these  amounts;  for,  as  has  already  been 
mentioned  in  the  case  of  iron,  the  amount  of  shrinkage 
varies  somewhat  under  varying  conditions.  For  the 
use  of  pattern-makers,  scales  or  rules  are  made.  The 
one  most  commonly  used  provides  for  an  allowance  of 
1/8  inch  per  foot ;  that  is,  the  rule  is  made  1/8  inch 
longer  than  the  standard  foot  rule,  and  each  "inch"  on 
the  rule  is  correspondingly  longer  than  the  standard 
inch.  The  use  of  one  of  these  scales,  however,  does 
not  solve  all  the  problems  in  shrinkage  that  may  arise 
in  practice.  For  instance,  if  it  is  required  to  make  a 
pattern  for  a  casting  8  feet  long,  and  an  allowance  of 
'  1/8  inch  per  foot  is  made  (which  would  be  the  case  if 
the  above  mentioned  scale  was  used),  the  casting  would 
be  longer  than  required  by  the  difference  between  1/8 
inch  and  i/io  inch  taken  eight  times,  viz.,  2/10  inch, 
or  nearly  1/4  inch.  In  such  a  case,  then,  it  would  be 
better  to  make  an  allowance  of  T/IO  inch  per  foot  (the 
approximate  shrinkage  of  iron).  Then  the  casting 
would  be  more  nearly  the  required  size.  Scales  or  rules 
can  be  bought  at  dealers,  graduated  for  the  other  shrink- 
ages above  mentioned. 

It  has  been  a  mooted  question  as  to  just  when  this 
shrinkage  or  contraction  takes  place  in  the  casting,  but 
it  is  generally  conceded  now  that  it  takes  place  in  pass- 
ing from  the  plastic  condition  to  the  solid  state.  All 
metals,  in  passing  from  the  liquid  to  the  solid  state, 


GENERAL  PRINCIPLES  89 

suffer  expansion  when  in  the  plastic  condition.  It  is 
this  feature  in  the  transition  that  enables  metals  to  take 
and  retain  the  impressions  of  the  molds  with  such 
fidelity.  Allowance  for  shrinkage  is  not  regarded  on 
patterns  that  measure  6  inches  or  less  in  any  one  direc- 
tion, as  the  rapping  of  the  pattern  will  usually  make  up 
for  any  shrinkage  that  may  take  place.  Patterns  that 
are  4  inches  or  less  in  size,  are  made  slightly  smaller 
than  the  desired  size  of  the  casting.  This  is  called  an 
allowance  for  shake.  It  is  not  regarded  unless  it  is 
necessary  that  the  casting  be  exact  in  size.  Patterns 
between  6  and  4  inches  may  be  made  without  regarding 
either  shrink  or  shake. 

In  building  machinery  it  is  often  necessary  to  fit  two 
castings  together.  Wherever  this  is  done,  the  two  sur- 
faces that  come  into  direct  contact  are  usually  machined 
in  some  way  in  order  to  obtain  a  smooth,  clean  surface 
of  metal.  This  is  the  case,  whether  the  two  surfaces 
are  to  slide  or  rotate  on  each  other,  or  whether  one  is 
simply  bolted  to  the  other,  and  is  called  an  allowance 
for  machining  or  finish.  When  the  words  "ma- 
chining" or  "finish"  are  used  in  connection  with 
pattern-making  they  always  refer  to  work  to  be 
done  on  a  casting.  A  part  of  a  pattern  that  repre- 
sents, a  surface  of  this  kind  on  the  casting,  must  be 
made  larger.  The  amount  of  this  allowance  is  gen- 
erally 1/8  inch,  measured  perpendicular  to  the  surface 
to  be  machined  or  finished.  If  the  surface  is  simply 
to  be  machined  to  fit  another  surface,  and  the  work  is 
comparatively  small,  this  will  be  enough.  But  if  it  is 
required  to  have  a  very  nice  finish,  free  from  all  sand 
holes,  or  if  the  work  is  large,  it  might  not  be  enough ; 


90  WOOD  PATTERN-MAKING 

in  some  cases  it  might  be  necessary  to  make  it  twice 
the  amount,  or  1/4  inch  on  each  surface..  Moreover, 
as  the  casting  increases  in  size,  its  irregularities  also 
increase,  so  that  a  larger  amount  must  be  allowed.  In 
the  case  of  large  work,  such  as  engine  beds,  the  allow- 
ance is  frequently  made  from  3/4  to  I  inch.  A  large 
allowance  is  especially  necessary  on  very  irregular  and 
new  work,  as  the  amount  of  distortion  caused  by  the 
strains  set  up  in  the  casting  by  shrinkage  is  very 
uncertain.  Large  steel  castings  are  usually  very  rough, 
and  also  become  more  or  less  distorted  in  cooling  and 
annealing,  so  that  it  is  necessary  to  allow  more  on  this 
account.  Of  course,  the  exact  amount  must  be  deter- 
mined by  the  circumstances  of  any  given  casting,  but 
there  should  be  enough  so  that  in  taking  the  first  cut, 
the  tool  used  may  get  beneath  the  sandy  scale  that  is 
always  present  on  a  casting,  and  still  leave  enough 
for  a  second  cut  at  least,  and  a  third  or  finishing  cut 
if  -necessary.  It,  therefore,  cannot  be  much  less  than 
1/8  inch. 

There  is  one  other  allowance  to  be  mentioned  that  is 
not  usually  called  for  in  making  machinery  pattern's, 
but  is  frequently  in  making  what  are  ^called  architect- 
ural patterns.  Some  castings,  because  of  their  varying 
thickness,  or  because  of  one  surface  being  more  exposed 
than  another,  therefore  cool  more  rapidly,  warp  or 
become  distorted  in  the  mold  when  cooling.  To  over- 
come this,  patterns  for  castings  of  shapes  that  are 
known  thus  to  warp,  are  made  of  such  a  shape  that  in 
cooling  they  will  assume  the  desired  shape.  This 
change  in  shape  of  patterns  is  called  an  allowance  for 
warp. 


CHAPTER  VIII 
MATERIALS 

Wood  is  the  material  used  for  a  large  majority  of 
patterns.  At  first  thought  it  would  Seem  that  wood  is 
a  particularly  unsuitable  material  to  be  used  in  matrices 
of  damp  sand,  and  to  be  subject  to  such  rough  usage  as 
the  ramming  and  rapping  of  a  pattern  necessarily  in- 
volves, but  there  are  several  reasons  why  wood  is  used. 
The  first  that  may  be  mentioned  is  that  it  is  easily 
worked  and  altered.  Secondly,  it  is  light  and  portable. 
Furthermore,  by  exercising  due  care  in  construction, 
its  disadvantages  may  in  a  degree  be  overcome.  The 
pattern-maker,  of  course,  meets  the  same  difficulties 
with  which  other  woodworkers  have  to  contend,  and 
such  as  interfere  with  the  durability  of  patterns.  The 
chief  one  among  these  is  due  to  the  tendency  of  wood 
to  shrink  and  swell,  which  causes  warping  and  change 
in  form  and  size.  This  cannot  be  wholly  overcome,  but 
by  arranging  the  different  pieces  in  a  given  pattern 
with  due  regard-for  this  natural  tendency,  it  may,  to 
a  degree,  be  counteracted.  To  prevent  warping,  it  is 
necessary  to  know  the  effect  this  tendency  has  upon 
the  individual  board ;  and  this  may  be  determined,  if 
the  position  of  the  board  in  the  log  is  known,  which 
may  be  determined  by  examining  the  end.  If  a  board 
is  cut  from  the  middle  of,  and  directly  through  the 
diameter  of  the  log,  it  is  not  very  likely  to  warp ;  but 
if  a  board  is  cut  from  a  position  midway  between  the 

91 


92  WOOD  PATTERN-MAKING 

heart  and  the  outside  of  the  log,  it  is  sure  to  do  so, 
for  it  will  assume  a  curved  outline  between  the  edges, 
the  heart  side  always  becoming  convex.  This  is  caused 
by  the  more  rapid  drying  of  the  board  on  the  sap  side. 
For  as  the  board  is  cut  through  the  concentric  cylindrical 
layers  of  which  the  log  is  composed,  the  outer  side  of 
the  board  contains  more  exposed  fibre  ends  and  more 
open  pores  than  the  heart  side.  Consequently,  the  sap 
side  of  a  board  gives  off  the  moisture  it  contains  more 
rapidly;  it  will  also  absorb  moisture  more  rapidly. 
In  view  of  this  fact,  the  sap  side  of  any  board  should 
be  placed  where  it  will  be  the  least  likelyto  be  exposed 
to  any  change  in  atmospheric  conditions.  That  is, 
whenever  it  is  possible,  this  side  of  the  board  should 
be  placed  on  the  inside  of  any  pattern-work. 

What  is  known  as  quarter-sawn  lumber  is  the  best 
for  pattern-work  and  all  woodwork,  because  it  is  not 
so  likely  to  warp  as  is  the  regular,  or  bastard-sawn. 
Quarter-sawn  lumber  is  lumber  that  is  sawn  approxi- 
mately parallel  with  the  medullary  ray.  The  trunk 
of  a  tree  is  made  up  of  concentric  cylindrical  layers, 
bound  together  with  radial  fibres,  which  are  known  as 
medullary  rays.  It  is  the  exposure  of  these  rays  that 
gives  to  quartered  oak  the  beauty  that  is  so  much 
prized.  However,  quartering  is  a  very  wasteful  way 
of  sawing  lumber,  and  involves  an  extra  cost.  But 
for  pattern  work  that  must  be  made  thin,  it  pays  to  use 
quarter-sawn  lumber,  even  if  it  does  cost  more. 

Another  very  important  factor  in  connection  with 
lumber  for  patterns  is,  that  it  should  be  thoroughly 
seasoned  before  being  used,  if  possible,  by  what  is 
known  as  the  natural  or  air-seasoning  process.  The 


MATERIALS  93 

seasoning  should  continue  for  at  least  two  years,  in 
order  that  the  natural  gums  of  the  wood  may  be  fixed ; 
that  the  rapid  drying  of  the  kiln  will  not  drive  them 
out,  and  in  that  way  make  the  wood  more  porous. 
Lumber  intended  for  pattern  work,  if  allowed  to  remain 
in  a  shed  with  a  waterproof  roof  for  two  years,  will 
give  better  results  than  lumber  exposed  to  all  sorts  of 
weather  for  six  months,  and  then  placed  in  a  dry  kiln 
to  finish  the  process.  For  i-inch  lumber  two  years 
is  enough ;  thicker  planks  will,  of  course,  need  more 
time,  say  four  years  for  2-inch.  However,  lumber 
cannot  be  so  thoroughly  seasoned  as  to  give  entire 
permanence  of  form  and  durability  to  patterns  made 
from  it. 

Besides  being  thoroughly  seasoned,  lumber  for  pat- 
terns should  be  straight,  and  even  in  grain,  not  too 
hard  to  be  easily  worked,  yet  not  so  soft  as  to  be  unduly 
injured  by  the  rough  usage  patterns  must  necessarily 
undergo  in  the  foundry.  There  is  no  wood  that  fulfills 
these  conditions  better  than  what  is  known  as  White 
Pine  (Pinus  Strobus),  sometimes  called  "cork  pine," 
because  of  the  cork-like  appearance  of  the  bark.  This 
wood,  when  thoroughly  seasoned,  will  retain  its 
shape  very  admirably  under  the  excessive  atmospheric 
changes  that  patterns  have  to  undergo  from  pattern- 
shop  to  foundry,  and  from  foundry  to  the  storage  loft. 
When  first  cost  need  not  be  considered,  and  it  should 
not  be  in  the  case  of  small  standard  patterns,  Mahog- 
any, what  is  known  in  the  market  as  Honduras  M.,  is 
the  best  wood  for  all  patterns;  it  is  very  even  and 
straight  in  the  grain,  not  so  hard  but  that  it  can  be 
easily  worked,  and  retains  its  form  and  size  to  a  remark- 


94  WOOD  PATTERN-MAKING 

able  degree.  One  thing  to  be  mentioned  in  this  connec- 
tion is  the  arranging  or  combining  the  several  pieces 
of  which  a  pattern  is  made  in  such  a  way  that  any 
shrinking  or  swelling  of  the  wood  shall  not  change  the 
shape  or  size  of  the  pattern.  This  is  an  important 
matter  in  some  classes  of  work,  and  should  have  the 
careful  consideration  of  the  pattern-maker,  especially 
in  the  case  of  standard  patterns.  If  this  is  done  it  will 
add  considerably  to  the  durability  of  a  pattern. 

There  is  one  principle  it  is  well  to  observe  in  com- 
bining the  several  pieces  of  wood  in  a  pattern,  and  that 
is  to  have  the  grain  of  the  wood  run  in  the  same  general 
direction,  or  as  nearly  so  as  possible,  so  that,  as  it 
shrinks  or  swells,  it  will  do  so  in  the  same  direction, 
and  therefore  will  not  distort  the  pattern. 

Special  patterns  are  often  made  of  brass,  iron,  white 
metal  or  aluminum.  These  metals  would  be  used  in 
light  or  curved  work,  and  also  when  a  large  number  of 
castings  of  the  same  size  and  shape  are  wanted.  With 
few  exceptions,  however,  original  patterns  are  made  of 
wood.  Statuary  and  other  ornamental  work  is  usually 
modeled  in  wax  or  clay,  which  serves  as  the  pattern. 
When  it  is  proposed  to  use  a  metal  pattern  for  the  pro- 
duction of  castings,  the  original  pattern  is  made  of 
wood  and  is  called  a  master  pattern  or  double-shrinkage 
pattern.  This  is  made  with  a  double-shrinkage  allow- 
ance, so  that  a  casting  made  from  it  will  still  be  large 
enough  for  the  pattern  from  which  to  make  the  castings 
wanted.  Patterns  made  of  wood  must  be  varnished 
or  they  will  soon  go  to  pieces. 


MATERIALS  95 

Sandpaper. 

In  pattern  work  sandpaper  should  be  used  with  dis- 
cretion. The  pattern  should  be  formed  as  nearly  to 
shape  and  size  and  finished  as  accurately  as  possible 
with  the  cutting  tools  before  sandpaper  is  used.  Under 
no  circumstances  should  sandpaper  be  used  for  cut- 
ting down  or  removing  any  considerable  amount  of 
stock,  or  for  doing  anything  that  can  be  done  with  tools. 
Otherwise  the  draft  and  the  accuracy  may  be  impaired. 
Sandpaper,  as  its  name  implies,  is  made  of  sharp  sand 
(quartz  or  garnet)  glued  on  paper.  It  is  graded  accord- 
ing to  the  grains  of  sand,  and  numbered  accordingly. 
The  grades  most  useful  to  the  pattern-maker  are  Nos. 
o  to  2.  No.  il/2  is  best  for  use  directly  on  the  wood, 
and  No.  i  for  the  varnished  surface.  Ordinarily,  sand- 
paper should  be  rubbed  across  the  grain  of  the  wood. 
In  the  last  two  or  three  years,  what  are  called  pattern- 
grinding  or  sanding  machines  have  been  introduced 
to  the  trade  to  take  the  place,  in  some  kinds  of  work, 
of  sandpapering  by  hand,  and  they  accomplish  the  work 
much  better  and  more  rapidly.  Any  kind  of  abrasive 
that  can  be  fastened  to  the  machine  may  be  used. 

Glue. 

In  pattern-making,  as  in  most  of  the  woodworking- 
trades,  glue  is  depended  on  for  adhesive  fastening.  For 
fastening  leather  fillets,  shellac  varnish  is  sometimes 
used.  Since  much  depends  on  the  character  of  the  glue 
used,  it  should  be  of  the  best.  There  are  many  kinds 
and  qualities  of  glue  on  the  market,  including  liquid, 
pulverized  or  ground,  and  sheet.  The  liquid  glue  is 


96  WOOD  PATTERN-MAKING 

always  ready  for  use  and  is  very  good  for  small  work. 
The  sheet  or  flake  form,  ground,  dissolved  and  applied 
hot  is  the  best  for  general  use.  Animal  glue  comes  in 
thin  sheets ;  it  is  the  best,  and  likewise  the  most  expen- 
sive. Of  late  years  the  large  manufacturers  of  glue  have 
taken  up  the  practice  of  grinding  these  sheets,  which 
makes  it  much  handier  for  use.  However,  this  enables 
dishonest  dealers  to  grind  the  cheaper  kinds  of  glue  and 
pass  them  off  as  the  best,  for  when  ground  it  requires 
an  expert  to  tell  the  difference,  but  when  it  is  cooked, 
the  odor  given  off  will  generally  indicate  its  quality.  As 
a  rule,  the  best  quality  of  glue  is  of  an  amber  color,  and 
the  sheets  rather  thin.  Whichever  kind  (excepting  of 
course  the  liquid)  is  used,  it  should  be  soaked  in  cold 
water  for  a  short  time  before  cooking;  only  a  small 
quantity  should  be  prepared  unless  the  shop  is  pro- 
vided with  a  steam  glue  heater  that  is  kept  hot.  Glue 
is  much  stronger  if  used  while  fresh,  as  frequent  heating 
and  cooling  destroys  its  strength.  To  obtain  the  best 
and  strongest  joint,  the  wood  should  be  slightly  warmed 
to,  say,  from  90  to  120  degrees,  and  the  glue  applied  as 
hot  as  possible,  and  the  work  quickly  clamped.  As  a 
rule,  the  harder  the  glue  the  better  it  will  resist  moist- 
ure. A  glue  that  will  resist  moisture  quite  effectively 
may  be.  made  by  adding  a  small  quantity  of  raw  linseed 
oil  to  glue  while  hot.  When  it  is  necessary  to  glue 
two  pieces  of  wood  together  so  that  the  joint  is  on  the 
end  grain,  the  end  should  first  be  given  a  coat  of  thin 
glue,  which  should  be  allowed  to  dry  before  applying 
the  glue  for  the  joint.  This  is  called  sizing  the  joint. 
Plenty  of  time  should  be  given  the  joint  to  dry — ten  to 
twelve  hours,  according  to  the  size  of  the  work,  will 


MATERIALS  97 

usually  be  enough  if  in  a  warm  and  dry  shop  or  room. 
Too  much  care  cannot  be  exercised  in  the  use  of  glue 
for  pattern  work ;  indeed,  it  is  not  advisable  to  use 
it  at  all  when  nails  or  screws  will  answer  the  purpose. 
However,  in  complicated  patterns  glue,  in  addition  to 
nails  and  screws,  will  add  to  the  rigidity  of  the  work, 
which  is  very  desirable ;  and  there  are  some  patterns 
that  cannot  be  made  without  it. 

Varnish. 

All  wooden  patterns  should  be  covered  with  some 
kind  of  protective  coating  so  as  to  prevent  as  much  as 
possible  the  absorption  of  moisture  from  the  damp 
sand  of  the  mold,  for  this  is  very  injurious  to  all  wood- 
work. The  protective  coating  should  be  of  such  a  nature 
as  to  be  unaffected  by  moisture  and  also  to  insure  a 
hard,  smooth  surface  that  will  "draw"  easily  from  the 
mold. 

In  practice  there  are  two  general  classes  of  varnishes 
used,  shellac  and  copal.  The  first,  which  is  the  kind 
most  generally  employed,  is  composed  of  common  gum 
shellac  cut  with  alcohol  and  colored,  if  so  wanted,  with 
some  kind  of  coloring  ingredient.  The  second  com- 
prises the  better  grades  of  copal  varnishes  used  by 
finishers.  This  may  also  be  colored.  By  changing  the 
color  of  the  varnish  employed,  it  is  possible  to  distin- 
guish between  core  prints  and  the  body  of  the  pattern, 
and  also  between  patterns  for  castings  of  different 
metals,  such  as  brass,  iron  and  steel. 

For  shellac  varnish  a  good  grade  of  gum  should  be 
used,  as  the  cheaper  grades  will  not  stand  up  to  the 
work.  This  is  usually  called  yellow  varnish.  Black 


98  WOOD  PATTERN-MAKING 

varnish  is  made  by  adding  lampblack ;  a  good  quality 
of  lampblack  should  be  used,  one  that  is  free  from  grit. 
Red  varnish  is  made  by  adding  some  red  powder, 
usually  Indian  red,  or  vermilion  (Chinese  is  best)  to 
the  yellow  varnish.  The  use  of  these  in  varnish  seems 
to  give  it  a  better  body  and  greater  durability.  Copal 
varnish,  however,  is  still  more  durable,  and  if  time 
(about  three  days)  can  be  given  it  to  dry,  it  is  much 
the  better  and  will  outlast  several  coats  of  shellac  var- 
nish. 

Beeswax 

Beeswax  is  used  for  making  small  fillets,  and  filling 
small  holes,  such  as  nail  holes,  etc.,  and  any  other  slight 
defect  in  either  material  or  workmanship.  It  may  also 
be  employed  for  making  a  slight  change  in  the  form  of 
a  pattern  that  is  not  much  used.  It  is  not  good  practice, 
however,  to  use  it  in  this  way  on  standard  patterns,  as 
it  is  very  liable  to  melt  and  run  out  in  the  storage  loft 
during  warm  weather. 

Wax  is  sometimes  used  for  coating  iron  patterns  to 
prevent  them  from  rusting.  To  cover  iron  patterns  with 
wax,  they  should  first  be  made  as  warm  as  they  can  be 
handled,  then  the  wax  should  be  spread  on  them  as 
evenly  as  possible  and  brushed  over  with  a  soft  brush. 

Nails. 

For  pattern  work,  what  are  known  as  wire  brads  are 
the  best  nails.  They  can  be  driven  almost  anywhere  in 
the  wood  without  splitting  it.  They  may  be  had  of 
all  lengths  from  one-half  inch  to  three  inches  and  of 
different  sizes  of  wire.  However,  owing  to  the  neces- 


MATERIALS  99 

sity  of  rapping  patterns  when  drawing  them  from  the 
mold,  it  is  always  best  to  use  screws  when  fastening 
the  different  parts  of  a  pattern  together.  They  are 
much  better  than  nails  on  account  of  the  clamping  effect 
they  give  to  the  pieces  to  be  joined.  This  is  a  very 
desirable  effect  in  the  case  of  standard  patterns.  An- 
other reason  why  screws  are  much  better  than  nails 
for  this  purpose  is  that  when  it  is  necessary  to  change 
or  repair  a  pattern,  screws  can  be  taken  out  without 
tearing  the  wood  of  the  pattern,  and  if  needed,  can  be 
replaced  exactly  in  the  same  place.  Screws  are  also 
handy  for  temporarily  securing  loose  parts  of  a  pattern, 
and  for  this  use  are  much  superior  to  nails  or  pins. 
When  screws  are  to  be  used  for  fastening  two  pieces 
of  wood  together,  holes  as  near  the  size  of  shank  of  the 
screw  as  possible  should  be  bored  through  the  upper 
piece.  If  this  is  not  done  the  screw  will  cut  a  thread 
in  both  pieces,  thus  hindering  the  clamping  effect  that 
is  otherwise  obtained  by  the  use  of  screws  for  this 
purpose. 

As  is  well  known  to  most  woodworkers,  end  grain 
wood,  especially  soft  wood,  does  not  hold  a  screw  very 
securely,  unless  some  special  method  is  used.  One  of 
the  best  ways  of  putting  screws  into  end  grain  is  to  bore 
a  hole  of  a  size  as  near  as  can  be  to  the  size  of  the  solid 
part  of  the  screw  at  the  bottom  of  the  thread.  The 
thread  of  the  screw  will  then  cut  its  way  into  the  wood 
without  disturbing  the  fiber  and  thus  the  full  shearing 
strength  of  the  wood  will  serve  to  hold  the  strain  put 
upon  the  screw.  The  hold  of  a  screw  in  end  wood  may 
be  increased  by  taking  it  out,  placing  a  small  amount 
of  glue  in  the  hole,  and  putting  the  screw  back  in  at 


100 


WOOD  PATTERN-MAKING 


once  while  the  glue  is  soft.  It  is  sometimes  necessary 
to  take  out  and  reinsert  screws  in  end  wood,  repeat- 
edly,— for  instance,  when  pattern  work  has  to  be  taken 
apart  for  convenience  in  molding.  In  such  cases,  sim- 
ply screwing  them  into  the  end  wood  should  not  be 
depended  upon,  as  they  get  loose  and  do  not  hold.  A 
good  way  to  overcome  this  difficulty  is  illustrated  by 
Fig.  72.  It  is  to  bore  a  hole  at  right  angles  to  the 
direction  of  the  screw  in  such  a  position  that  the  screw 
shall  pass  through  it;  fill  this  hole  with  a  hardwood 


FIG.  72 


plug,  bore  a  hole  of  suitable  size  for  the  screw  and 
insert  the  screw.  If  now  the  screw  from  frequent 
taking  out  and  screwing  in  becomes  loose,  the  plug 
may  be  taken  out  and  another  put  in  its  place.  As 
noted  elsewhere,  screws  make  a  much  stronger  fasten- 
ing than  nails  and  should  always  be  employed  in  pat- 
tern work  that  is  to  be  much  used,  as  in  the  case  of  a 
standard  pattern. 


CHAPTER  IX 
FILLETS 

Sharp  corners  on  a  casting,  whether  inside  or  out- 
side, generally  detract  greatly  from  its  appearance,  and 
also,  in  the  case  of  internal  angles  especially,  injure  its 
strength.  This  being  the  case,  sharp  corners  must  be 
avoided  in  the  pattern,  as  the  casting  will  be  of  the 
saitie  shape  as  the  pattern.  The  weakness  due  to  sharp 


FIG.  73. 


FIG.  74. 


corners,  especially  in  the  case  of  internal  angles,  is 
caused  by  the  way  iron  acts  in  cooling,  or  in  passing 
from  the  molten  to  the  solid  state.  There  are  always 
more  or  less  strains  set  up  in  a  casting  by  the  shrinkage 
or  contraction  that  takes  place  at  that  time.  As  the 
iron  hardens  the  crystals  seem  to  arrange  themselves 
in  such  a  manner  that  their  lines  of  strength  are  per- 
pendicular to  the  faces  of  the  casting.  For  instance, 
in  a  casting  of  the  general  shape  shown  by  Fig.  73  these 
lines  arrange  themselves  as  shown  by  the  short  lines 

101 


102  WOOD  PATTERN-MAKING 

drawn  perpendicular  to  each  face  and  thus  leave  the 
space,  A,  open  or  honeycombed ;  consequently  the  cast- 
ing will  be  very  weak  through  the  line,  B,  C,  and  when 
a  strain  is  put  upon  it,  it  will  be  likely  to  break.  In 
some  shapes  of  castings  these  strains  caused  by  shrink- 
age will  of  themselves  crack  the  casting  at  this  point 
and  at  all  similar  sharp  internal  angles.  If  the  above 
casting  is  made  with  a  fillet,  or  rounded-in-angle,  this 
is  not  so  likely  to  be  the  case,  and  if  it  is  made  as  repre- 
sented by  Fig.  74  it  will  be  just  as  strong  at  that  point 
as  at  any  other.  For,  as  will  be  noticed,  there  is  no 
place  for  this  irregular  crystallization  to  take  place. 
In  view  of  these  well-known  facts,  all  internal  angles 
should  be  thus  rounded  in  or  "filleted"  on  the  pattern. 
When  fillets  are  used  on  patterns  for  the  purpose  of 
strengthening  the  casting  only,  care  must  be  taken  not 
to  make  them  of  too  large  radius,  as  this  will  be  very 
liable  to  counteract  the  very  effect  desired  by  making 
the  casting  so  thick  at  that  point  that  the  metal  will 
be  drawn  away  from  that  part  by  shrinkage  and  so 
make  the  casting  porous  and  weak.  Some  large  fly- 
wheels have  burst  because  of  this.  Therefore,  in  large 
work  the  best  practice  is  to  make  the  fillets  compar- 
atively smaller  than  they  are  made  in  small  or  light 
work.  There  can  be  no  arbitrary  rule  given  for  the 
radius  of  the  curve  of  a  fillet.  If  the  two  webs  or  other 
parts  to  be  connected  by  a  fillet  are  approximately  the 
same  thickness,  then  a  radius  equal  to  one-half  of  that 
thickness  will  be  very  effective  in  adding  strength  to 
the  casting  and  will  at  the  same  time  please  the  molder. 
In  molding  a  pattern  of  the  general  shape  of  Fig.  75 
that  for  some  reason  has  to  be  pulled  or  drawn  from  the 


FILLETS 


103 


mold  in  the  direction  of  the  arrow,  a  very  sharp  corner 
of  sand  will  be  left  at  the  point  C.  As  the  pattern  is 
pulled  up  past  it,  a  slight  movement  of  the  pattern  side- 
wise  would  break  it ;  then  as  soon  as  the  pattern  became 
clear  of  the  mold,  the  sand  would  fall  down  into  it,  thus 


FIG.  75. 

making  what  the  molder  would  call  a  dirty  mold.  It 
would  cause  him  some  trouble  to  remove  this  sand  from 
the  mold,  and  it  must  be  all  cleaned  out,  for  otherwise 
it  would  surely  make  a  poor  spot  on  the  casting  and 
might  render  it  unfit  for  the  use  to  which  it  was  in- 
tended to  be  put.  This  applies  to  all  internal  angles  in 
patterns.  Therefore,  for  the  molder's  benefit,  as 
well  as  to  strengthen  the  casting,  it  is  best  to  "round 
in"  any  internal  angles.  Fillets  may  be  made  of  wood, 
wax  or  leather.  The  last  is  undoubtedly  the  best;  it 
also  is  the  most  expensive,  at  least  in  its  first  cost. 
Wood  is  generally  used  for  straight  work,  the  best 
practice  being  to  fit  and  glue  a  piece  of  wood  of  the 
right  size  into  the  angle  and  allow  it  to  dry  before  cut- 
ting the  required  curve.  By  working  the  curve  after 
it  is  glued  in  place,  the  tendency  of  thin  edges  of  wood 


104'  WOOD  PATTERN-MAKING 

to  curl  when  made  wet,  which  of  course  is  done  in  the 
gluing,  is  entirely  overcome.  There  is  no  objection 
to  using  wood  for  this  purpose  if  the  wood  that  is  used 
is  straight  in  grain,  and  if  the  grain  of  the  wood  of 
which  the  fillet  is  made  lies  in  the  same  direction  as 
the  grain  of  the  wood  composing  the  part  of  the  pattern 
to  which  it  is  glued.  Leather  is  the  best  material  of 
which  to  make  fillets,  since  it  is  elastic  enough  to  come 
and  go  with  the  wood  as  it  shrinks  and  swells.  It  is 
as  permanent  as  the  pattern  itself,  gives  a  very  smooth 
finish,  and  is  easily  applied.  Wax  is  not  very  good 
except  for  very  small  fillets  or  for  temporary  patterns. 
It  should  not  be  used  for  fillets  on  standard  pattern 
work  as  it  is  likely  to  melt  and  run  out  when  exposed 
to  summer  heat  in  the  storage  loft. 

In  making  and  applying  fillets  of  wood,  the  process 
is  something  like  this :  First,  a  piece  of  wood  of  the 
proper  length  is  ripped  out  square,  so  that  each  side 
is  equal  to  the  radius  of  the  curve  of  the  proposed  fillet. 
One  corner  is  fitted  to  the  angle  proposed  to  be  filleted ; 
it  is  better  if  this  does  not  exactly  fit  clear  into  the 
angle — that  is,  the  fillet  piece  may  be  a  little  loose  at 
the  apex  of  the  angle,  but  should  fit  tightly  on  the  other 
two  sides  of  the  triangle.  When  this  is  properly  fitted 
the  remaining  or  outside  angle  may  be  planed  off  with 
the  jack-plane  so  as  to  make  a  triangular-shaped  piece, 
Fig.  76.  The  third  side,  the  one  last  made,  is  a  good 
place  in  which  to  drive  brads  for  holding  the  piece  in 
place  while  the  glue  is  drying.  The  brads  should  be 
placed  about  four  inches  apart.  When  a  sufficient 
number  of  brads  have  been  started,  the  glue  may  be 
applied  to  the  piece,  the  piece  set  into  the  angle  and  the 


FILLETS 


105 


brads  driven  in  as  far  as  can  be,  while  still  leaving  the 
heads  protruding,  so  that  they  may  be  pulled  out  when 
the  glue  is  dry.  When  the  glue  is  thoroughly  dry  the 
nails  may  be  pulled  out,  and  the  required  curve  cut 
or  worked  with  gouge  and  sandpaper,  making  it  as 
nearly  tangent  as  possible  to  the  two  sides  it  connects. 


In  order  to  apply  leather  fillets  successfully,  a  tool 
known  as  a  "filleting  tool"  is  needed.  It  consists  of  a 
sphere  of  iron,  or,  still  better,  of  brass,  fastened  to  a 
short  rod  somewhat  smaller  than  the  sphere.  The 
radius  of  the  sphere  should  be  equal  to  that  of  the 
fillet.  After  the  leather  fillet  is  cut  to  the  required 
length,  moderately  thick,  clean  glue,  not  too  hot,  is 
applied;  the  leather  is  placed  in  the  angle,  and  the 
filleting  tool  is  run  along  the  angle,  pressing  the  leather 
firmly  into  place.  The  pressing  should  be  done  heavily 
enough  to  squeeze  out  all  surplus  glue,  which  should  be 
cleaned  off  at  once  with  a  piece  of  cloth  or  waste, 
dampened  with  hot  water ;  then  the  surface  thus  made 
wet  should  be  wiped  as  dry  as  possible  with  a  dry  piece 
of  the  same  material.  In  order  to  secure  the  best  re- 


106  WOOD  PATTERN-MAKING 

suits  in  performing  this  operation,  the  filleting  tool 
should  be  hot.  This  may  best  be  accomplished  by 
putting  the  tool  into  hot  water  for  a  few  seconds. 

Wax  fillets  are  put  in  in  the  following  manner : 
Some  wax  is  softened  by  heat  and  rolled  into  a  small 
cylinder,  the  diameter  of  which  is  governed  by  the  size 
of  the  fillet.  It  is  then  laid  in  the  angle.  The  filleting 
tool  before  mentioned  is  warmed  enough  to  soften  the 
wax,  and  the  cylinder  is  pressed  into  the  angle.  The 
wax,  being  softened,  conforms  to  the  shape  of  the  tool, 
which,  as  it  is  passed  along,  leaves  a  circular  surface 
tangent  to  the  two  sides  of  the  angle.  The  surplus  wax 
should  be  cleaned  off  up  to  the  line  made  by  the  tool. 
This  makes  a  very  nice  job,  and  is  a  good  way  of  mak- 
ing fillets  for  patterns  that  are  not  to  be  much  used. 
There  are  on  the  market  small  presses  that  turn  out 
cylinders  of  wax  for  making  wax  fillets.  They  are  so 
arranged  that  different  sizes  of  cylinders  are  made  for 
different  sizes  of  fillets.  These  small  cylinders  of  wax 
are  also  used  for  venting  cores  and  molds.  These  ma- 
chines save  considerable  time  and  trouble  in  this  kind 
of  work,  and  also  do  it  more  satisfactorily. 


CHAPTER  X 
CORES 

When  castings  are  to  be  made  with  holes  through 
them,  or  with  internal  cavities,  a  projecting  body  of 
sand  must  either  be  made  in  the  mold  at  the  same  time 
as  the  other  parts  of  the  mold  are  made,  or  else  be 
introduced  into  the  mold  after  the  pattern  is  removed 
or  pulled  out.  These  projecting  bodies  of  sand  are 


FIG.  77. 

called  cores.  When  the  pattern  can  be  withdrawn  from 
the  mold  and  leave  a  core  as  a  part  of  the  mold,  it  is 
said  to  leave  its  own  core.  This  is  illustrated  by  Fig. 
77.  This  illustration  represents  a  mold  with  the  pat- 
tern b  removed,  thus  leaving  the  core  a  projecting 
above  the  lower  surface  of  the  mold.  When  the  cope 
is  closed  the  cope  sand  will,  of  course,  touch  the  upper 
surface  of  this  core ;  when  the  mold  is  filled  with  melted 
metal,  it  cannot  flow  into  the.  space  occupied  by  the 

107 


108  WOOD  PATTERN-MAKING 

core.  The  result  is  that  the  casting  will  have  a  hole 
through  it  the  shape  of  the  core  a.  Where  patterns 
cannot  be  so  made,  and  molded  with  the  ordinary  appli- 
ances of  the  foundry,  to  form  their  own  cores,  there  is 
added  to  the  pattern  an  attachment  or  projection  that 
forms  a  mold  or  recess  in  the  sand,  into  which  a 
separate  core  may  be  placed.  These  attachments  are 
called  core-prints. 

Cores  that  are  made  separate  from  the  mold  are 
usually  what  are  called  dry-sand  cores,  although  green- 
sand  cores  are  sometimes  made  in  the  same  way.  A 
simple  form  of  pattern  for  a  mold  with  a  dry-sand  core 
is  represented  by  Fig.  68,  parts  A  and  B  being  core- 
prints. 

A  dry-sand  core  is  made  in  a  separate  device  called 
a  core-box.  In  the  case  of  a  symmetrical  core,  a  core- 
box  is  made  only  for  a  small  portion  of  it.  For  a 
cylindrical  core  only  a  half  box  need  be  made,  two 
cores  from  such  a  box  being  pasted  together,  thus  form- 
ing a  complete  core.  This  same  principle  may  be  used 
in  the  case  of  very  large  work.  A  symmetrical  mold, 
like  one  for  a  fly-wheel,  may  be  built  up  almost  entirely 
with  cores. 

Core-boxes  require  as  great  care  in  their  manufacture 
as  patterns,  and  as  much  thought  must  be  given  to 
their  shape,  durability  and  finish.  The  shape  of  a  pat- 
tern is  nearly  like  the  required  casting ;  but  the  inside 
of  the  core-box,  which  is,  of  course,  the  necessary  part, 
is  just  the  reverse,  resembling  more  nearly  the  shape  of 
the  mold.  When  cores  are  made  in  boxes  and  inserted 
in  the  mold,  it  is  necessary  that  they  be  supported  in 
such  a  way  that  there  will  be  no  chance  for  a  change 


CORES 


109 


of  position  by  the  action  and  weight  of  the  molten 
metal  as  it  is  being  poured  into  the  mold.  To  give 
this  support,  special  recesses  are  made  in  the  mold  to 
receive  them.  These  recesses  are  made  by  the  core- 
prints  previously  mentioned.  The  core  should  exactly 
fill  the  recesses  left  by  the  core-prints,  and  this  part 
of  the  core  should  be  large  enough  to  support  the  core 


FIG.  79. 


properly  in  place,  so  that  the  sand  of  the  mold  will  not 
be  crushed  out  of  shape  by  the  weight  of  the  core,  nor 
by  the  action  of  the  metal  while  being  poured  into  the 
mold. 

Core-prints  should  be  given  more  taper  than  the 
pattern  itself,  so  that  the  work  of  withdrawing  the  pat- 
tern from  the  mold  may  not  be  unduly  increased  by 
their  presence,  and  also  that  the  core  may  be  the  more 
easily  adjusted  to  its  proper  position.  In  the  case  of 
plain  cylindrical  cores,  whose  length  does  not  exceed 
five  times  their  diameter,  or  of  such  as  may  be  stood  on 
end  while  drying,  a  full  box  may  be  constructed  and 
the  cores  made  whole.  This,  of  course,  saves  the  time 


110  WOOD  PATTERN-MAKING 

of  the  core-maker,  as  he  does  not  have  to  cement  the 
two  halves  together.  A  core  made  in  this  way,  with 
its  box,  or  mold,  is  represented  by  Fig.  79.  As  it  is 
necessary  to  vent  cores,  boxes  that  form  a  compelte 
core  should  be  provided  with  some  means  of  doing  it. 
The  most  common  way  is  to  bore  holes  through  the 
sides  of  the  box  that  form  the  ends  of  the  prints  of  the 
core,  so  that  rods  (large  wires)  may  be  placed  in  the 
core  while  being  made.  These  rods  are,  of  course, 
pulled  out  before  the  core  is  taken  from  the  box.  In 
making  all  core-boxes  and  core-prints,  care  should  be 
taken  that  the  part  of  the  box  corresponding  to  the 
print  on  the  pattern  should  be  exactly  the  same  size 
and  shape  as  that  print,  so  that  when  the  core  is  set 
into  the  mold  it  will  exactly  fit. 

All  core-prints  should  be  of  ample  size,  so  that  their 
impression  will  hold  the  cores  in  their  place,  and  so 
that  the  weight  of  the  core  and  the  weight  and  action  of 
the  melted  metal  will  not  change  their  position.  It 
is  well  to  remember  that  the  material  that  must  do  this 
holding  is  only  loam,  or,  as  it  is  technically  called, 
sand.  It  therefore  requires  a  comparatively  large  sur- 
face to  make  it  secure  against  the  weight  and  action 
of  melted  metal  during  the  process  of  pouring  it  into  the 
mold.  On  account  of  the  varying  shapes  and  condi- 
tions there  can  be  no  exact  rule  given  for  the  sizes  of 
these  prints,  that  will  cover  all  cases.  The  length  of 
the  core-prints  for  a  plain  cylindrical  horizontal  core 
should  approximate  its  diameter,  and  its  shape  should 
be  cylindrical.  For  a  vertical  core  of  this  same  general 
shape,  the  print  should  be  the  frustrum  of  a  cone,  with 
the  large  end  next  the  pattern ;  the  height  should  be 


CORES 


111 


1  inch,  and  the  diameter  of  the  small  end  1/2  inch  less 
than  the  large  end. 

In  core  work  that  requires  prints  of  other  shapes 
than  those  mentioned  above — that  is,  where  the  opening 
into  or  through  the  casting  is  not  round,  then  the  prints 
should  correspond  in  shape. 


„  —  v 

1 

!*  -I  i 

'    i  ' 
I   | 

1  ( 

ll'^ 

„  3.  „ 

__  _  -j-  ^ 

The  making  of  core-prints  properly  located  and  of 
correct  size  and  shape  is  a  very  important  part  of  the 
pattern-maker's  art,  especially  so  from  the  molder's 
standpoint.  Prints  that  do  not  show  the  exact  position 
of  the  core  may  be  very  misleading  and  may  result  in 
the  loss  of  the  casting.  One  form  of  core  where  this 
mistake  might  easily  occur  and  not  be  noticed  until 
after  the  casting  is  made  is  illustrated  by  Fig.  80.  The 
figure  represents  a  casting  that  requires  a  cylindrical 
horizontal  core  with  a  part  enlarged  to  make  the  cavity, 
A,  which,  it  will  be  noticed,  is  not  in  the  center  of  the 


112  WOOD  PATTERN-MAKING 

length  of  the  casting.  In  this  case,  if  both  core  prints 
are  made  of  the  same  size,  the  molder  will  be  quite 
likely  to  set  the  core  wrong  end  to.  The  molder  would 
not  be  altogether  to  blame  for  this  mistake,  as  he  gen- 
erally does  not  have  anyting  to  guide  him  in  this  work 
except  the  pattern  and  core-box  furnished  by  the  pat- 
tern-maker. But  if  one  core-print  is  made  larger  than 
the  other,  then  it  will  be  impossible  for  him  to  set  it 
incorrectly  without  deliberately  cutting  the  mold.  In 
all  core  work,  therefore,  the  prints  should  be  of  such 
size  and  shape  that  it  will  be  impossible  to  set  the  core 
into  the  mold  in  any  other  than  the  correct  position. 
For  cylindrical  cores,  this  is  the  best  method,  and  is 
sure  to  accomplish  the  desired  result.  Sometimes  it 
is  required  that  a  cylindrical  core  should  lie  in  the  mold 
in  a  certain  position  with  regard  to  its  circumference. 
In  that  case  it  would  be  necessary-  to  change  the  shape 
of  at  least  one  of  the  prints,  making  one  or  both  square 
so  that  the  core  cannot  be  set  wrong  or  revolve  after 
being  set. 

Some  prints  for  horizontal  cores  are  not  made  long 
enough,  consequently  the  metal  when  poured  into  the 
mold  will,  by  its  own  static  pressure,  raise  or  displace 
the  core  and  make  the  casting  thinner  on  the  cope  side 
because  of  this  movement. 

It  is  advisable  to  make  the  prints  of  cylindrical  hori- 
zontal cores  about  equal  in  length  to  the  diameter  of  the 
core.  This  may  seem  excessive  and  in  some  cases  it 
may  be,  but  it  had  better  be  too  long  than  too  short. 
When  it  becomes  necessary  to  make  them  shorter  than 
this  on  account  of  the  size  of  the  flask  to  be  used,  or  of 
the  core  oven,  and  the  casting  is  quite  heavy,  it  is  good 


CORES  113 

practice  to  imbed  a  plate  of  iron  in  the  mold  for  the  core 
to  rest  on ;  thus  the  weight  of  the  core  will  be  distrib- 
uted over  a  larger  area  of  sand  than  the  core-print  alone 
would  afford. 

A  great  many  castings  are  lost  because  the  lower 
print  of  vertical  cores  are  made  nearly  parallel,  or  with 
the  ordinary  pattern  draft.  The  probable  cause  of  this 
is  that  the  core  does  not  go  down  to  the  bottom  of  the 
mold  since  the  sand  is  cut  down  by  the  core  on  setting ; 
so,  when  the  cope  is  closed,  being  too  long,  it  breaks  the 
mold  around  the  print  of  the  core,  allowing  metal  to 
flow  into  the  vent  and  thereby  causing  the  casting  to 
"blow."  This  may  be  overcome  to  a  large  degree  by 
tapering  the  lower  print  as  is  usually  done  in  the  case 
of  the  upper  one.  If  this  is  attended  to  there  can  be  no 
trouble  in  setting  the  core.  Indeed,  in  the  case  of  small 
cores,  the  molder  can  set  them  enough  faster  to  pay 
for  the  extra  work  of  pasting  such  cores  together.  As 
this  is  the  main  objection  to  this  shape  of  print,  viz., 
the  necessity  of  making  the  cores  in  halves,  it  will  be 
more  than  overbalanced  by  the  advantage  of  the  greater 
facility  and  rapidity  with  which  the  cores  can  be  set, 
to  say  nothing  about  the  larger  output  of  sound  cast- 
ings. 

The  subject  of  taper  core-prints  for  vertical  cores  is 
one  of  considerable  importance,  especially  from  the 
molder's  standpoint.  It  is  well  to  adopt  some  standard 
taper,  so  that  if  a  core-print  is  lost,  another  may  be 
made  of  the  correct  size  whether  the  core-box  is  in  sight 
or  not.  Probably  the  best  taper  for  the  purpose  is  one 
of  one-fourth  inch  to  one  inch  in  height.-  This  is  an 
easily  remembered  taper  and  will  give  entire  satisfaction 


114 


WOOD  PATTERN-MAKING 


to  the  molder.  This  taper  can  be  employed  for  all  verti- 
cal prints  large  or  small  (the  smaller  sizes  being  reduced 
in  length)  one  inch  is  long  enough  for  any  size  of  cylin- 
drical vertical  core.  A  good  rule  to  follow  for  cores 
less  than  one  inch  in  diameter,  is  to  make  the  length 
of  the  print  equal  to  the  diameter,  while  preserving  the 
same  taper.  It  might  be  objected  that  one  inch  is  too 
short  for  large  cores,  say  of  12  inches  or  more  in 
diameter.  But  there  is  not  much  strain  on  the  print — 


FIG.  81. 

that  is,  on  the  print  in  the  sand  of  the  mold  which  holds 
the  core  in  place — for  it  simply  locates  the  core.  Nearly 
all  the  strain,  if,  to  be  sure,  there  is  any,  comes  on  the 
end  of  the  core.  Therefore,  any  extra  length  given 
the  print  would  be  of  no  advantage,  and  one  inch  is  as 
good  as  a  greater  length.  One  reason  why  there  is 
but  a  slight  strain  on  the  sides  of  these  prints  is  that 
the  metal  on  entering  the  mold  completely  surrounds 
the  core  so  that  the  pressure  is  practically  equal  in  all 
directions.  This,  however,  is  not  the  case  with  the  hori- 
zontal cylindrical  core.  As  has  been  already  men- 
tioned, a  taper  of  1/4  inch  on  each  side  is  the  best.  This 
is  illustrated  in  Fig.  81,  where  it  is  reduced  to  a  system. 


CORES 


115 


In  this  system  the  dimensions  of  the  prints  for  cores 
that  are  less  than  i  inch  in  diameter  are  derived  from 
the  diameter  of  the  core ;  for  instance,  if  it  is  required 
to  provide  for  a  core  that  is  7/8  inch  in  diameter,  the 
length  of  the  prints  will  be  7/8  inch,  or  the  diameter 
of  the  core,  the  large  diameter  also,  7/8  inch,  the  small 
diameter  7/16  inch  or  one-half  the  large.  Therefore, 
in  using  this  system,  and,  knowing  the  diameter  of  the 
core,  the  dimensions  of  the  prints  may  be  derived  there- 
from. Now  if  a  print  is  lost,  as  often  happens,  another 
can  be  made  without  seeing  the  core-box,  if  this  system 
is  carried  out  for  all  cores  of  this  kind. 

A  summary  of  the  above  for  the  shapes  and  sizes  of 
cylindrical  core  prints  is  as  follows : — 


SHAPE. 

DIAMETER. 

LENGTH. 

HORIZONTAL. 

Cylindrical. 

Same  as  Diame- 
ter of  the  Core. 

Equal  to  the  Diame- 
ter. 

VERTICAL. 

Frustum  of  a 
Cone. 

Large  end  =  Di- 
ameter of  Core. 
See  Fig.  81. 

1  in.  when  Diameter 
of  the  Core  is  1  in. 
or  more.  SeeFig.81. 

CHAPTER  IX 
HOLDERS'  JOINTS  OR  PARTINGS 

The  jointing  of  patterns  is  fundamental,  and  must  be 
considered  from  two  points  of  view ;  that  of  the  molder, 
and  that  of  the  woodworker.  The  first  is  concerned 
more  particularly  with  the  removal  of  the  pattern  from 
the  mold,  or,  as  the  molder  expresses  it,  pulling  the 
pattern.  The  second  is  constructional,  and  into  it  en- 


FIG.  82. 


FIG.  83. 


ters  the  combination  and  arrangement  of  the  different 
pieces  of  wood  composing  the  pattern.  The  joints  that 
are  arranged  for  the  purpose  of  removing  the  pattern 
from  the  mold  are  usually  called  partings,  or  pattern- 
makers' partings,  and  strictly  speaking,  are  not  joints. 
The  joints  made  in  the  construction  of  the  pattern  are 
true  joints,  and  should  be  made  as  nearly  perfect  as 
possible,  since  the  strength  and  durability  of  the  pat- 
tern depends  largely  on  their  efficiency  as  joints. 

The   first  mentioned  of  these  joints,   the  molder's 
partings,  will  be  considered  in  this  chapter.     Whether 

116 


PARTINGS 


117 


a  pattern  is  made  correctly  or  not,  from  the  molder's 
standpoint,  will  depend  largely  on  the  understand- 
ing that  the  pattern-maker  has  of  these  partings, 
and  of  their  position  in  the  mold  itself.  In  order  to 
explain  these  points  a  few  examples  will  be  used.  It 
requires  at  least  one  of  these  molder's  partings  for 
every  pattern,  as  the  mold  must  consist  of  two  bodies  of 
sand,  so  that  the  pattern  may  be  taken  out.  The  sim- 
plest form  of  pattern  is  a  square  block  like  that  repre- 
sented by  Fig.  82.  The  parting  will  be  made  on  the  line 


FIG.  84. 


A  B,  the  part  of  the  mold  below  that  line  being  in  the 
nowel ;  in  this  case  all  the  mold  will  be  in  the  nowel, 
the  cope  forming  the  top  surface  only.  The  next  in 
point  of  simplicity  is  known  as  a  simple  parted  pattern, 
and  is  represented  by  Fig.  68,  on  page  77.  In  a  mold 
made  from  this  pattern,  one  half  would  be  in  the  nowel, 
and  one  in  the  cope,  as  represented  at  the  right  in 
Fig.  83.  The  line  C  D  is  the  parting  line  of  the  mold 
and  also  of  the  pattern.  In  this  form  of  pattern,  it  will 
be  noticed,  the  molder's  parting  and  the  pattern-maker's 
parting  exactly  coincide.  When  a  pattern  is  so  made 
that  the  partings  can  be  arranged  in  this  way,  the  mold- 
ing may  be  very  easily  and  quickly  done.  The  process 
of  molding  such  a  pattern  is  described  in  Chapter  VI. 
Fig.  84  may  be  considered  typical  of  a  large  class  of 


118 


WOOD  PATTERN-MAKING 


pattern  work.  It  is  a  pattern  for  a  small  car  wheel 
having  a  central  web.  The  molder's  parting  will  be 
made  on  line  A  B.  No  parting  is  required  in  the  pat- 
tern because  of  the  position  of  the  molder's  parting, 
which  is  made  along  the  line  A  B  on  the  outside  of  the 


FIG.  85. 


pattern ;  and  on  the  inside  of  the  rim  the  cope  sand  will 
extend  down  to  the  top  of  the  web.  The  hub  or  boss  C 
is  usually  left  loose  so  it  will  lift  with  the  cope  sand. 


FIG.  86. 

Fig.  85  represents  a  pattern  of  a  double  flange  wheel, 
and  is  a  good  example  of  a  class  of  patterns  where  the 
molder's  and  pattern-maker's  joints  do  not  coincide. 
This  would  need  what  is  called  a  three-part  flask,  mean- 
ing that  the  mold  is  composed  of  three  distinct  bodies 
of  sand,  which,  of  course,  involves  the  making  of  two 
molders'  partings.  One  of  these  will  come  in  the 
centre  of  each  flange  on  lines  A  B  and  C  D.  The  pat- 


PARTINGS 


119 


tern  will  be  parted  at  E  F.  The  sand,  or  cores,  that 
will  form  the  part  of  the  mold  at  G  and  H  will  be  lifted 
with  the  cope  down  to  the  upper  line  of  the  web. 

The  mold  for  a  worm  wheel  is  another  good  example 
of  molding  where  the  parting  of  the  pattern  does  not 
coincide  with  that  of  the  mold.  Fig.  86  will  make  this 
quite  clear.  The  pattern  will  be  parted  along  the  line 
A  B  ;  the  molder's  partings,  of  which  there  must  be  two 


FIG.  87. 


will  come  on  the  lines  C  D  and  G  H.  All  of  the  teeth 
will  come  in  the  middle  part,  or  cheek,  included  in  the 
space  K.  The  two  halves  will,  of  course,  be  drawn 
from  the  mold  in  opposite  directions,  the  inner  curves 
of  the  rim,  and  the  taper  of  the  hub,  affording  plenty 
of  draft.  There  is  another  form  of  molder's  parting 
known  as  an  irregular  parting,  that  must  frequently  be 
used  on  account  of  the  shape  of  the  pattern.  The  pat- 
tern represented  by  Fig.  87  is  an  example  of  this  form 
of  parting.  In  the  molding  of  this  pattern  the  molder's 
parting  will  be  made  along  the  dotted  line  D  D,  so  that 


120 


WOOD  PATTERN-MAKING 


most  of  the  mold  will  be  in  the  nowel,  which  is  very 
desirable,  as  it  leaves  less  sand  to  be  lifted  by  the  cope. 
As  indicated  by  the  tapered  prints  shown  at  A'  and  B' 
in  Fig.  122,  a  core  will  be  used  for  forming  a  round  hole 
through  the  casting.  Another,  but  a  more  simple  joint 
of  this  kind  is  shown  by  Fig.  88,  which  represents  a 


-:* 


FIG.  88. 


cast-iron  bracket.  The  parting  of  the  mold  will  be 
made  along  the  dotted  line  A  B.  If  a  number  of  com- 
paratively small  brackets  of  this  shape  is  wanted,  the 
pattern  can  be  parted  through  the 'central  web,  or  a 
follow  board  can  be  made  and  fitted  to  a  one-piece 
pattern,  which  would  be  the  better  way.  A  follow 
board  is  a  board  to  which  a  pattern  that  must  have 
an  irregular  parting  has  been  fitted,  the  surface  of  which 
has  also  been  cut  to  form  the  parting  or  joint  on  the 
sand  of  the  nowel.  A  follow  board  takes  the  place  of 


PARTINGS 


121 


the  molding  board  for  molding  a  pattern  that  must, 
because  of  its  shape,  have  an  irregular  parting. 

A  contrivance  frequently  used  in  molding,  called 
skewering  on  loose  pieces,  saves  considerable  time  and 
work  in  both  pattern-shop  and  foundry.  An  example 
of  this  is  illustrated  by  Fig.  89,  which  represents  a  part 
of  a  cast-iron  base  for  a  woodworking  machine.  The 


whole  casting  is  cored  out ;  and,  for  convenience  in 
molding,  the  pattern  has  been  boxed  up  to  form  a  one- 
piece  pattern,  to  be  pulled  from  the  mold  in  the  direc- 
tion indicated  by  the  arrow.  If  the  two  bosses,  A  and 
B,  were  fastened  on,  they  would  tear  up  the  sand.  In 
order  to  prevent  this  they  are  skewered  on — that  is, 
held  in  place  temporarily  with  wire  skewers,  as  shown. 
As  the  mold  is  being  rammed  up,  after  sand  enough  has 
been  rammed  around  the  bosses  to  hold  them  in  place, 
the  skewers  are  pulled  out.  This,  of  course,  allows 
the  main  pattern  to  be  pulled  out,  thus  leaving  in 
the  mold  these  loose  pieces  which  can  be  pulled  side- 


122 


WOOD  PATTERN-MAKING 


wise  into  the  mold.  Of  course,  this  pattern  could 
be  parted  through  the  center  line,  but  that  would 
entail  a  large  amount  of  extra  work  in  both  the  foundry 
and  the  pattern-shop.  By  the  use  of  this  method,  there- 
fore, the  extra  work  of  making  another  parting  is  saved. 


FIG.  90. 


FIG.  91. 


Another  way  sometimes  adopted  for  forming  projec- 
tions on  a  casting  is  made  clear  by  Figs.  90  and  91. 
They  represent  a  hollow,  cylindrical  casting,  with  a 
flange  on  both  ends,  a  projecting  boss  for  a  pipe  on  one 
side,  about  midway  of  its  height,  and  an  opening 
through  the  top.  The  pattern  will  have  to  be  parted 
on  the  line  CC,  and  will  require  a  three-part  flask,  with 
molder's  parting  along  line  B  B.  To  form  the  projec- 
tion on  the  side,  one  of  two  methods  may  be  adopted — 


PARTINGS 


123 


the  use  of  a  core-print  and  core,  or  a  core  only,  to  be 
set  in  place  at  the  time  of  ramming  up  the  mold.  If 
the  second  method  is  used,  all  that  the  pattern-maker 
needs  to  do  is  to  make  a  core-box  with  a  pattern  projec- 
tion located  in  it.  This  core-box  is  represented  by  Fig. 
92.  If  the  first  method  is  adopted,  a  core-print  will  have 
to  be  put  on  the  side  of  the  pattern,  so  as  to  extend 


iecftorz  Thrw  A-B—  • 


FIG.  92. 


from  the  top  parting  down  to  a  point  just  below  the  pro- 
jection. If  a  hole  is  to  be  cored  thru  the  projection,  this 
would  be  the  best  way  of  doing  the  job. 

The  examples  given  above  of  molder's  joints  do  not 
introduce  nearly  all  the  ways  and  means  employed  by 
the  molder  for  making  molds ;  but  they  do  give  a  good 
general  idea  of  the  most  common  ways,  and  will  afford 
such  suggestions  to  the  beginner  in  pattern-making 
as  to  enable  him  to  make  patterns  so  that  they  can  be 
"pulled"  without  injury  to  the  mold.  This  should  be 


124  WOOD  PATTERN-MAKING 

the  first  consideration  of  the  pattern-maker,  as  on  it 
depends  in  a  large  degree  the  accuracy  of  the  casting. 
If  the  mold  is  injured  in  any  way  by  the  pulling  of  the 
pattern,  so  that  the  molder  has  to  mend  it,  the  casting 
is  rarely  correct  in  shape.  In  the  next  chapter  the 
matter  of  constructional  joints  is  taken  up — that  is,  the 
building  of  wood  patterns  from  the  viewpoint  of  the 
woodworker. 


CHAPTER  XII 
CONSTRUCTIONAL  JOINTS 

In  a  consideration  of  this  part  of  the  general  subject 
of  pattern-making,  two  things  must  be  given  promi- 
nence, viz.,  the  strength  and  durability  of  the  pattern, 
and  its  permanence  of  form.  This  latter  is  very  likely 
to  be  interfered  with  by  the  absorption  of  moisture  from 
the  damp  sand,  thereby  causing  the  wood  to  swell,  and 
parhaps  to  warp.  The  amount  of  moisture  thus  ab- 
sorbed depends  upon  the  time  the  pattern  has  to  remain 
in  the  mold,  and  upon  the  condition  of  its  protective 
coating  of  varnish.  To  overcome  any  change  likely  to 
take  place  from  this  cause,  several  methods  of  arrang- 
ing the  various  pieces  of  which  the  pattern  is  built  up, 
are  used.  The  particular  method  to  be  employed  in  a 
given  case  depends  on  the  size  and  shape  of  the  pattern, 
and  also  depends,  to  a  degree,  on  whether  a  large  num- 
ber of  castings  is  wanted  or  only  one.  In  order  to 
secure  the  requisite  permanence  of  form,  it  is  better, 
other  things  being  equal,  to  build  a  pattern  of  several 
pieces  rather  than  to  cut  it  out  of  one  piece.  For  then 
the  warping  in  the  whole  pattern  is  reduced  to  a  mini- 
mum. Tn  small  patterns,  however,  this  warping  may 
be  disregarded ;  therefore,  a  small  pattern  may  be  cut 
from  a  single  piece  of  wood.  This  matter  of  construc- 
tional joints  may  be  most  easily  comprehended  by 
studying  examples  of  forms  likely  to  be  required. 

When  thin  disks  are  wanted  it  is  best  to  build  them 

125 


126 


WOOD  PATTERN-MAKING 


up  of  three  layers  with  the  grain  of  the  pieces  running 
tangentially  to  a  small  circle  in  the  center,  as  illustrated 
by  Fig.  93.  The  grain  of  the  wood  must  run  parallel 
to  the  longest  side  of  each  sector.  After  the  pieces 
have  been  fitted  together,  a  groove  is  cut  in  the  edge 
of  each,  in  which  tongues  of  wood  are  glued  and  driven 
as  illustrated  in  the  right-hand  view,  Fig.  93.  When 
one  disk  has  been  glued  up  and  the  glue  has  dried,  the 


FIG.  93. 


sectors  for  the  other  disks  may  be  glued  directly  to  it, 
with  the  joints  running  across  the  others,  the  angle 
depending  on  the  number  of  sectors  used  to  form  the 
circle.  This  makes  a  very  rigid  construction  and  one 
which  will  not  warp. 

If  in  building  a  pattern  a  thin,  wide  board  is  required 
and  the  other  parts  of  the  pattern  are  of  such  shape  that 
they  do  not  afford  to  it  sufficient  support  to  keep  it  from 
warping,  a  good  way  is  to  rip  the  board  up  into  strips 
from  2  to  4  inches  wide  (according  to  the  width  of  the 
required  board)  and  then  glue  the  strips  together,  with 
each  alternate  strip  reversed,  as  shown  at  A,  Fig.  95. 


CONSTRUCTION  JOINTS 


127 


In  this  way  the  warping  will  be  reduced  to  the  mini- 
mum because  the  alternate  pieces  are  inclined  to  warp 
in  opposite  directions. 

A  good  way  to  support  patterns  of  this  general 
shape  during  the  process  of  molding  is  illustrated  by 
Fig.  95.  The  additional  pieces  B  and  C  are  called 
counter  ribs.  The  recesses  made  by  them  in  the  sand 
will  be  filled  by  the  molder,  or,  as  he  expresses  it, 


FIG.  95. 


they  are  "stopped  off  in  the  mold,"  and  therefore  will 
not  appear  on  the  casting.  The  shape  of  these  counter 
ribs,  which  is  more  clearly  shown  at  D,  indicate  to  the 
molder  that  they  are  to  be  stopped  off  in  the  mold. 
Whenever  possible  these  should  be  put  on  the  pattern 
so  they  will  come  in  the  nowel  of  the  mold.  These  are 
also  called  "stop-off"  pieces.  Another  way  of  building 
patterns  which  are  round  and  flat  and  are  supported  by 
segments  running  around  them,  is  to  make  the  flat  part 
of  several  strips  rather  than  of  a  wide  board.  This  is 
illustrated  in  Fig.  96.  These  strips  should  not  be  glued 


128 


WOOD  PATTERN-MAKING 


together,  but  held  in  position  by  the  segments  that  are 
built  on  to  them.  If  the  pattern  is  more  than  12  inches 
in  diameter  on  the  inside,  it  is  advisable  to  insert  at 
least  one  dowel  in  each  of  the  joints  between  these 
strips  to  keep  them  from  springing  sidewise.  This 
need  be  done  only  for  three  or  four  of  the  joints 
near  the  center.  A  slip  tongue  joint  may  also  be  used 
instead  of  dowels. 


; 


FIG.  96. 


Another  way  to  overcome  the  effect  of  shrinking  and 
swelling  in  large  patterns  is  the  use  of  what  is  termed 
open  joints.  If  it  is  required  to  build  a  large  pattern 
that  is  flat  and  comparatively  thin,  either  circular  or 
square,  it  should  be  built  as  shown  in  Fig.  97 — that  is, 
the  sides  should  not  be  built  up  by  gluing  narrow 
boards  together,  but  they  should  be  laid  side  by  side 
with  open  joints  between,  of  from  1/16  inch  to  1/8  inch 
in  width,  and  a  slip-tongue  inserted.  If  the  boards 
expand  with  moisture  the  width  of  the  pattern  as  a 
whole  does  not  increase ;  the  only  effect  is  to  partly 


CONSTRUCTION  JOINTS 


129 


close  these  open  spaces.  If  the  boards  shrink  the  only 
effect  is  that  the  spaces  increase  in  width.  As  work  of 
this  general  shape — that  is,  of  large  area  but  compar- 
atively thin  in  cross-section — is  usually  stiffened  with 
ribs  and  flanges,  the  fact  that  the  joints  are  open  will 
not  materially  affect  the  rigidity  of  the  pattern.  If  a 


FIG.  97. 


case  should  occur  where  there  was  not  support  enough 
in  the  pattern  itself,  then  the  boards  could  be  held  in 
place  as  shown  in  Fig.  97,  by  a  method  which  is,  prac- 
tically, paneling.  A  frame  is  made  as  for  a  panel  door, 
and  the  ends  of  the  boards  fitted  into  a  groove.  This 
method  may  be  used  in  connection  with  what  is  known 
as  boxing  up  a  pattern.  This  is  illustrated  in  Fig.  98. 
Open  joints  are  represented  at  a,  a,  a,  Fig.  97.  This 
term,  boxing  up,  is  used  in  speaking  of  a  class  of  pat- 
terns that  are  built  of  comparatively  thin  lumber,  the 
pattern  itself,  being  large,  making  a  box-like  structure 


130 


WOOD  PATTERN-MAKING 


that  is  both  light  and  strong.  This  method,  boxing  up, 
is  frequently  used  for  large  patterns  which,  if  made 
solid,  would  be  unduly  heavy  and  would  be  especially 
liable  to  be  affected  by  moisture  or  dryness.  The  rab- 
beted joint  should  always  be  used  at  the  corners  in 
boxing  up  a  pattern  that  is  of  a  square  or  rectangular 
cross-section.  This  is  illustrated  by  Fig.  98.  If  the 
pattern  was  to  be  pulled  from  the  mold  in  the  direction 


FIG. 


indicated  by  the  arrow,  and  was  built  as  at  a,  Fig. 
98,  then  any  change  due  to  shrinking  or  swelling  of  the 
relative  position  of  pieces  b  and  c  would  leave  an 
uneven  surface  on  the  vertical  side  which,  on  being 
pulled  from  the  mold,  would  be  likely  to  tear  up  the 
sand  and  thereby  cause  the  molder  some  trouble.  If 
the  joints  are  arranged  as  at  A,  Fig.  98,  this  cannot 
occur.  This  form  of  joint  has  another  advantage,  for 
if  the  joint  were  simply  a  butt  joint,  the  ramming  of  the 
sand  of  the  cope  down  on  the  face  E  would  be  likely  to 
drive  the  top  board  down  below  the  edges  of  the  sides, 
but  in  this  case  the  piece  E,  being  rabbeted  into  A  and 
C,  cannot  be  driven  down. 


CONSTRUCTION  JOINTS 


131 


Fig.  99  represents  an  example  of  another  type  of 
hollow  work,  which,  however,  is  not  called  boxing  up, 
but  lagging  or  lagging  up.  This  method  may  be  denned 
as  the  building  of  patterns  of  cylindrical  shape  with 
longitudinal  strips  that  run  parallel  with  the  axis  of  the 
proposed  cylinder.  The  figure  represents  a  section 
of  the  pattern  of  a  pipe  or  column  of  any  diameter  over 


FIG.  99. 


four  or  five  inches.  A  A  is  the  joint  of  both  pattern  and 
mold.  B  B  are  cross-bars  of  polygonal  shape  on  which 
the  strips  or  lags  are  laid  and  fastened  with  glue  and 
screws.  The  lags  are  also  glued  to  each  other  except 
on  the  line  A  A. 

Fig.  100  illustrates  another  way  of  building  by  lag- 
ging. In  this  way  much  narrower  strips  are  used,  there- 
by reducing  the  work  of  turning  and  also  requiring  less 
lumber.  The  parts  for  the  core-prints  are  built  up  first, 
and  then  the  lags  for  the  rest  of  the  pattern  are  fitted 
and  glued  and  screwed  to  these,  as  is  indicated  by  the 
figure.  Should  the  body  of  the  cylinder  be  long,  two 
or  more  semi-circular  discs  must  be  used  to  insure 
rigidity.  Fig.  101  shows  how  this  method  of  building 


132 


WOOD  PATTERN-MAKING 


up  may  be  used  for  large  cylindrical  core  boxes.  If 
the  work  is  done  accurately,  the  work  of  finishing  the 
inside  of  the  box  is  reduced  to  a  minimum. 

When  annular  patterns  of  6  inches  or  more  in  diame- 
ter are  wanted  they  are  made  by  what  is  known  as 
building  up  with  segments.  This  is  illustrated  by  Fig. 


FIG.  100. 


FIG.  101. 


102,  and  when  properly  done  makes  a  very  strong  con- 
struction. The  several  pieces  should  be  cut  from  the 
board  in  such  a  way  that  the  grain  of  the  wood  follows 
the  circle  as  near  as  may  be.  Therefore,  in  laying  out 
the  segments  the  chords  of  the  curves  should  be  parallel 
to  the  grain  of  the  wood.  In  building  patterns  of  this 
type,  a  number  of  short  segments  are  sawn  out  and 
glued  in  courses,  one  over  the  other,  with  the  end  joints 
alternating,  or  breaking  joints.  When  the  glue  is  dry 
the  correct  outline  is  imparted  by  turning  or  otherwise. 


CONSTRUCTION  JOINTS 


133 


By  this  construction  shrinkage  in  the  segments  is  re- 
duced to  practically  nothing. 

Examples  of  constructional  joints  used  in  still  an- 
other type  of  pattern,  sometimes  termed  plate  work,  is 
represented  by  Figs.  103  and  104.  Fig.  103  shows  a 
frame  cut  from  the  solid  wood,  18  inches  wide  and  2  feet 
6  inches  long,  by  i  inch  thick.  It  is  clear  that  strength 


FIG.  102. 


and  permanence  of  form  is  entirely  lacking  in  bars  A  A 
A.  Contrast  this  with  the  construction  in  Fig.  104.  In 
the  latter  there  cannot  be  any  material  alteration  in 
width  or  length,  in  general  or  local  dimensions,  and 
there  is  the  maximum  of  strength.  The  frame  is  made 
of  five  narrow  strips.  Alternative  methods  of  making 
half-lap  joints  are  shown.  At  the  corners  plain  halving 
is  shown.  At  D  the  dovetailed  form  of  halving  is  illus- 
trated. The  plain  halving,  if  properly  made,  glued 
and  screwed,  is  very  strong  and  permanent.  For  stand- 
ard patterns,  however,  it  is  advisable  to  employ  the 
dovetail  form. 


134 


WOOD  PATTERN-MAKING 


Another  example  of  this  same  type,  but  of  a  very 
distinct  form,  is  shown  in  Fig.  119.  The  finished  cast- 
ing is  shown  in  Fig.  118.  It  will  be  noticed  that  the 
joints  are  of  the  half-lap  form.  This  figure  (Fig.  119) 
shows  the  plate  part  of  the  pattern  only,  made  up  of 
three  pieces.  The  pieces  are  so  arranged  that  wherever 
there  is  a  curve  there  is  wood  with  the  grain  running 


r 


FIG.  104. 


practically  tangent  to  it ;  consequently,  if  the  joints  are 
properly  made  and  glued,  it  can  be*  worked  into  shape 
without  being  broken  out.  Moreover,  there  is  wood 
enough  at  all  the  angles  so  that  the  fillets  may  be 
worked  in  the  solid  wood  instead  of  separate  pieces 
being  glued  in  for  the  fillets.  For  standard  plate  work 
it  is  always  best  to  do  this,  even  if  it  does  take  wider 
material.  The  added  durability  will  more  than  pay  for 
the  extra  lumber,  and  then  it  also  saves  the  time  of 
making  and  gluing  in  the  separate  pieces. 

Round  corners  may  be  formed/ as  shown  by  Fig.  105. 
In  this  case  the  two  pieces,  A  and  B,  are  joined  in  the 


CONSTRUCTION  JOINTS 


135 


usual  way  with  a  butt  joint  as  at  C ;  the  piece  D  is  glued 
into  the  angle  and  allowed  to  stand  long  enough  to  dry ; 
then  the  corner  is  worked  to  the  required  form  outside 
and  inside.  In  work  of  this  kind  it  is  best  to  work  the 
inside  first,  because  the  piece  can  usually  be  held  better 
if  the  outside  corner  is  square  than  if  it  is  rounded. 
The  block,  after  being  fitted  to  the  angle,  may  be  sawed 
or  planed  to  form,  as  indicated  by  line  E.  This  can  be 


FIG.  105. 


done  more  easily  before  than  after  it  is  glued  in  place. 
As  pattern-making  is  one  of  the  most  comprehensive 
of  trades,  and  the  demands  of  the  engineering  profes- 
sion for  complicated  castings  are  limitless,  it  is  impos- 
sible to  anticipate  the  next  form  a  pattern-maker  will 
be  called  on  to  make.  This  being  the  case,  only  general 
methods  can  be  considered  in  a  volume  of  this  size. 
The  joints  and  methods  of  construction  that  have  thus 
far  been  considered  are  those  most  frequently  em- 
ployed in  pattern-making.  Special  examples  of  types 
of  pattern-making  will  next  be  taken  up,  for  which 
one  or  more  methods  of  construction  will  be  given  in 
detail. 


CHAPTER  XIII 

TYPICAL  PATTERNS 

Before  taking  up  the  subject  of  making  special  types 
of  patterns,  certain  matters  that  apply,  not  only  to 
special  types,  but  to  all  patterns,  may  be  considered. 
One  of  these  is  the  preparation  of  the  lumber.  This 
consists,  in  the  first  place,  of  cutting  roughly  to  size, 
the  several  pieces  required  for  making  the  proposed 
pattern.  They  are  then  allowed  to  stand  for  as  long  a 
time  as  the  job  will  allow,  so  that  they  may  warp  into 
and  assume  a  nearly  permanent  form.  If  this  is  done, 
when  they  are  cut  to  the  final  shape  they  will  not  again 
warp  and  change  the  original  form  of  the  pattern.  This 
additional  seasoning  is  necessary,  because  lumber  will 
change  more  or  less  in  shape  when  much  of  it  is  cut 
away,  exposing  a  surface  that  has  heretofore  been  on 
the  inside  of  the  plank  or  board.  The  foregoing  consti- 
tutes the  first  step  and  may  be  termed  cutting  the  stuff 
roughly  to  size. 

The  next  step  is  planing  up  one  or  two  sides  of  each 
piece  to  a  true  plane,  and  marking  them  as  working 
faces.  Usually  these  planes  should  be  made  at  right  an- 
gles to  each  other.  This  is  quite  important,  as,  generally 
speaking,  the  accuracy  of  the  work  will  depend  to  a  large 
degree  upon  the  accuracy  of  these  two  faces.  All  lumber 
to  be  used  in  making  patterns  should  be  planed  by  hand, 
before  being  put  into  the  pattern,  especially  if  a  flat 
surface  is  desired.  The  ordinary  rotary  knife  planer 

136 


TYPICAL  PATTERNS 


137 


will  not  plane  stuff  flat,  therefore  the  hand  plane  must 
be  used.  If  there  is  a  Daniels  planer  in  the  shop  it  may 
be  used  to  plane  one  side  of  the  board  ;  the  other  may  be 
passed  through  the  ordinary  planer.  But  even  if  this 
is  done,  the  lumber  should  be  planed  by  hand  to  insure 
a  good  finish,  as  the  rotary  knife  will  leave  the  surface 
more  or  less  corrugated. 


4  —  3f—  i 

I  * 

~!  i 

i 

L,              I'' 

•y 

1 

1 

1 

I 

/*ll     over 

FIG.  106. 

The  simplest  patterns  are  those  which  are  made  in 
one  piece,  and  which  require  no  coring,  although  the 
castings  themselves  may  be  hollow.  In  commencing  a 
pattern,  one  must  first  decide  how  it  is  to  be  removed 
from  the  sand,  and  where  the  parting  should  be,  if  one 
is  needed.  A  simple  one-piece  pattern  around  which 
to  form  a  mold  with  a  dry-sand  core,  is  exemplified 
by  the  stuffing  box  gland  shown  in  Fig.  106.  This 
figure  shows  the  finished  casting,  which  is  to  be 


138  WOOD  PATTERN-MAKING 

finished  all  over.  This  typifies  a  very  large  class  of 
patterns  which  must  be  cast  on  end.  It  is  what  is 
generally  known  as  a  stuffing-box  gland.  The  finished 
casting  is  represented  by  Fig.  106,  the  finished  pattern 
by  Fig.  107  and  the  requisite  core-box  by  Fig.  109.  Fig. 
106  represents  also  the  drawing  that  would  be  sent  to 
the  shops.  The  gland  is  made  from  this  drawing. 

Considering  this  pattern  from  the 
molder's  standpoint,  it  is  clear  that 
if  it  is  molded  endwise,  with  the 
flange  up,  and  if  the  molder's  part- 
ing is  made  along  the  top  of  the 
flange,  it  can  be  readily  pulled. 
The  draft  in  this  case  should  be 
1/8  inch  for  12  inches.  Each  core- 
FIG.  108.  print  ghou^  be  j  jnch  iong. 

When  the  amount  of  draft  and  finish  is  decided  on, 
it  is  a  good  plan  to  make  a  full-size  sketch  of  the 
pattern  as  it  will  appear  when  ready  for  the  molder, 
and  with  all  required  dimensions  plainly  shown  on  it. 
This  should  be  done  before  one  begins  to  make  the 
pattern.  Indeed,  one  may  well  follow  this  method  in 
the  case  of  every  pattern,  for  thereby  many  mistakes 
and  much  loss  of  time  will  be  avoided. 

According  to  the  drawing,  Fig.  106,  this  gland  is  to 
be  finished  all  over,  so  that  in  making  the  pattern  there 
must  be  allowance  for  both  finish,  or  machining,  and 
draft.  As  none  of  the  dimensions  are  over  6  inches  in 
any  one  direction,  shrinkage  may  be  disregarded.  As 
this  pattern  is  to  be  pulled  from  the  mold  endwise,  the 
draft  on  the  outside  will  have  to  be  like  that  shown  in 
Fig.  70  on  page  85.  One  way  to  make  a  pattern  for  this 


TYPICAL  PATTERNS 


139 


casting  is  shown  in  Fig.  108.  If  it  is  made  in  this  way, 
it  may  be  molded  and  leave  its  own  core,  but  the  hole 
can  not  have  its  opposite  sides  parallel.  It  is  usual  to 
allow  double  the  amount  of  draft  on  the  inside  for  all 
small  cores  similar  to  this 
one.  This  would  make  con- 
siderable more  work  for  the 
machine  shop  if  the  hole 
had  to  be  finished.  For  this 
reason,  if  a  large  number  was 
wanted,  the  pattern  would 
be  made  as  described  in  the 
following  paragraphs. 

To  make  this  pattern  it 
will  be  necessary  to  build  up 
a  block  of  wood  that  is  at 
least  324X324X7  inches  long. 
The  best  way  to  do  this  is 
to  use  two  pieces  1^2  inches 

thick,  and  one  piece  24  mcn  thick,  gluing  them  all  to- 
gether, with  the  thinner  one  between  the  other  two. 
In  gluing  up  work  of  this  kind,  it  is  always  best  to  have 
the  thicker  pieces  on  the  outside ;  for  if  the  piece  on  the 
outside  is  too  thin,  it  will,  during  successive  moldings, 
be  likely  to  become  loosened  on  account  of  the  action  of 
the  damp  sand  on  the  glue.  If  the  two  outside  pieces 
are  thin,  the  wedge-shaped  parts  that  are  formed  by  the 
turning  will  be  so  thin  that  they  will  be  very  likely  to 
curl  under  the  influence  of  the  damp  sand.  .  As  soon  as 
the  glue  is  quite  dry,  the  corners  may  be  cut  off  with 
an  axe  or  a  chisel  and  mallet.  The  piece  is  now  ready 
to  be  mounted  in  the  lathe,  and  should  be  turned  to  a 


FIG.  109. 


140 


WOOD  PATTERN-MAKING 


cylinder  of  3^5  inches  in  diameter,  which  is  the  outside 
dimensions  of  the  flange.  Now,  laying  a  rule  alonj? 
the  tool  rest  up  against  the  cylinder,  point  off  the 
measurements  as  indicated  by  the 
drawing,  preferably  commencing 
at  the  right-hand  end — that  is, 
next  to  the  back  or  dead  center  of 
the  lathe.  By  commencing  at  that 
point  any  surplus  material  will  be 
left  at  the  other  end,  so  that  it  will 
not  be  necessary  to  get  so  close  to 

the  chuck  or  driving  center  with 
FIG.  110.  the   tools         pirst)   thenj   make   a 

mark  about  1/16  inch  from  the  right-hand  end  for 
the  end  of  the  print.  From  this  point  measure  I 
inch  for  the  length  of  the  print ;  from  this  3%  inches 
for  distance  from  the  end  of  the  pattern  to  the  under 
side  of  the  flange ;  from  this  point  measure  y%  inch  for 
the  thickness  of  the  flange ;  from  this  mark  measure  i 
inch  for  the  length  of  the  print  on  this  end.  Check  up 
by  measuring  total  length  between  the  outside  marks, 
which  should  be  6l/%  inches.  Now  hold  the  point  of  a 
pencil  at  each  of  these  marks,  allowing  the  side  of  the 
pencil  to  lay  on  the  tool  rest ;  give  the  belt  of  the  lathe 
a  pull  which  will  turn  the  cylinder,  making  a  mark  all 
the  way  around  it.  Now  cut  the  cylinder  to  the  re- 
quired size  below  the  flange,  remembering  that  the 
core-prints  will  have  to  be  tapered,  because  this  will 
be  a  vertical  core.  Now,  if  the  successive  steps  have 
been  done  correctly,  the  pattern  will  be  like  Fig.  107. 
The  top  print  should  be  made  loose  for  the  convenience 
of  the  molder. 


TYPICAL  PATTERNS  141 

The  next  thing  will  be  the  making  of  the  core-box  in 
which  to  make,  or  form  or  mold  the  dry-sand  core. 
This  box  is  shown  by  Fig.  109.  This  being  a  symmet- 
rical core,  one  half  box  will  be  enough.  To  make  this 
we  proceed  as  follows  :  Take  a  piece  of  straight-grained 
pine,  of  such  a  width  that  after  the  semi-circular  groove 
forming  the  body  of  the  box  is  cut  out,  there  will  be  left 
about  y±  inch  on  each  side.  In  this  case,  the  box 
being  2^4  inches  in  diameter,  and  il/2  inches  for  the  two 
sides,  the  width  of  the  piece  will  be  3%  inches.  The 
depth  of  the  groove  will,  of  course,  be  \*£  inches,  and 
there  should  beat  least  J/$  inch  thickness  of  wood  below 
this,  which  will  make  the  required  block  2x3^  inches 
and  5  inches  long.  The  block  should  be  planed  on  all 
sides ;  one  of  the  wide  sides  (for  the  top  of  the  box) 
and  its  adjacent  narrow  sides  are  to  be  straight,  par- 
allel, and  exactly  at  right  angles  to  each  other.  To 
lay  out  the  lines  for  the  inside  of  the  box,  fasten  the 
block  in  the  vise  with  one  end  even  with  the  top  of 
bench,  or  vise.  Now  set  the  dividers  to  the  radius  of 
the  required  curve,  i%  inches,  and  put  one  leg  of  the 
dividers  in  between  the  block  and  the  vise  jaw,  on 
the  side  intended  for  the  top  of  the  box,  approximately 
in  the  center  of  the  side ;  then  describe  a  semi-circle 
on  the  end  of  the.  block,  as  shown  at  Fig.  no.  Now 
with  the  gage  set  to  the  distance  c  to  a,  make  a  mark 
along  the  top  or  face  side  for  the  the  whole  length  from 
the  point  a,  then  extend  the  gage  to  point  b,  making 
another  line  the  whole  length  of  the  block.  On  the 
other  end  make  another  semi-circle,  connecting  with 
the  ends  of  the  gage  lines.  This  completes  the  laying 
out  of  the  core-box.  The  wood  must  now  be  taken  out 


142 


WOOD  PATTERN-MAKING 


just  to  these  lines.  This  may  be  done  in  two  ways, 
the  better  of  which  is  by  the  use  of  the  core-box  plane. 
This  is  a  plane  whose  face  instead  of  being  just  one 
surface,  is  composed  of  two  surfaces  set  at  right  angles 
to  each  other,  as  shown  by  Fig.  in.  The  cutting  iron 


FIG.  111. 

is  narrow,  and  ground  to  an  acute  angle,  so  as  to  con- 
form to  the  shape  of  the  plane  at  the  apex  of  the  angle 
forming  the  two  sides  of  the  face  of  the  plane.  The 
principle  of  its  construction  and  use  is,  that  the  greatest 
inscribed  angle  in  a  semi-circle  is  a  right  angle.  The 
whole  of  the  wood  on  the  inside  of  the  semi-circle  can- 
not be  cut  out  with  this  plane,  so  first  use  a  gouge  to 
cut  it  out  to  within  }/8  incn  of  the  mark;  next  cut 
it  exactly  to  line  along  both  gage  marks ;  then,  holding 
the  plane  in  such  a  way  that  the  fingers  of  the  left  hand 
will  form  a  guide  to  keep  the  plane  to  the  line,  cut  a 
shaving  along  the  line  on  the  side  farthest  from  the 
operator.  This  is  illustrated  by  Fig.  112,  in  which  the 
upper  curved  line  represents  the  work  as  done  by  the 
gouge,  and  the  semi-circle  immediately  below  it  is  the 
circle  to  which  the  wood  is  to  be  cut.  There  is  now  a 
guide  for  both  sides  of  the  plane,  so  that  by  exercising 


TYPICAL  PATTERNS  143 

a  little  care  the  plane  may  be  passed  along  throughout 
the  length  of  the  block,  cutting  a  shaving  at  each 
stroke.  This  may  be  continued  until  about  one-third 
of  the  whole  is  worked  out.  Now  the  block  may  be 
turned  end  for  end,  and  the  other  side  treated  in  the 
same  way  down  to  about  mid- 
way of  the  distance ;  then  turn 
the  block  again  and  finish  the 
other  side.  This  will  make  a 
very  neat  and  accurate  job  if 
the  plane  is  in  proper  condition. 
Another  way  by  which  the 
plane  may  be  started  is  to  nail 
a  thin  strip  of  wood  along  the 
gage  line  as  represented  at  a, 
Fig.  112.  This  is  used  as  a  FlG 

guide  for  the  plane.    After  the 

groove  has  been  cut  down  a  short  distance  (about 
1/16  inch),  this  extra  piece  must  be  removed  to  the 
other  side  and  again  used  as  a  guide.  This  guide 
piece  must  be  taken  away  before  working  the  groove 
down  very  much,  for  if  allowed  to  remain,  it  would 
change  the  size  of  the  semi-circle  made  by  the  plane. 
The  cutting  iron  of  the  plane  should  be  so  sharpened 
and  set  as  to  cut  on  one  side  only,  preferably  on  side 
A,  Fig.  in.  If  it  is  allowed  to  cut  on  both  sides,  and 
used  as  indicated  by  Fig.  112,  it  will  cut  the  groove 
too  large,  making  the  core-box  larger  in  diameter 
than  wanted.  This  plane  may  be  made  to  do  more 
accurate  work  by  having  a  shallow  rabbet  out  along 
one  side  of  the  apex  of  the  angle,  as  shown  at  A, 
Fig.  TIT.  If  this  is  not  done  the  cutting  iron  must  be 


144  WOOD  PATTERN-MAKING 

set  out  a  little  beyond  the  face  of  the  plane  in  order  to 
cut  a  shaving,  and  so  will  make  the  semi-circular  groove 
larger  than  wanted. 

Another  way  to  cut  out  this  part  of  the  core-box  is 
to  use  a  gouge  to  remove  almost  all  the  material,  using 
a  round  plane  to  finish  with.  Doing  the  job  in  this  way 
will  involve  the  use  of  a  straight  edge  to  test  the 
straightness  of  the  work  from  end  to  end.  For  this 


FIG.  113. 

purpose,  a  straight  edge  with  a  thin  cross-section  is 
necessary.  A  try-square  if  long  enough,  is  a  very  good 
tool  for  this  purpose. 

The  core-box  plane  is  almost  indispensable  for  mak- 
ing core-boxes  of  the  shape  represented  by  Fig.  113, 
for  what  may  be  called  conical  cores.  As  the  curve 
changes  continually  throughout  the  entire  length,  it  is 
almost  impossible  to  make  a  cavity  that  is  uniform,  if 
one  uses  the  gouge  and  round  plane.  A  straight  edge 
and  templet  must  be  used  frequently  to  test  the  work. 
But  the  core-box  plane  overcomes  all  these  difficulties, 
and  if  only  the  two  sides  of  the  cavity  are  correctly 
located,  and  then  worked  to  the  lines  with  the  gouge, 
the  plane  will  do  the  rest  of  the  work.  There  are  ma- 


TYPICAL  PATTERNS  145 

chines  on  the  market  which  do  this  kind  of  work  very 
accurately  and  rapidly. 

Whichever  method  is  used  in  making-  this  part  of 
the  core-box,  it  needs  to  be  smoothed  on  the  inside  with 
sand  paper.  If  the  box  is  small,  this  is  best  done  with 
sandpaper  placed  around  a  cylinder  of  wood,  the  cyl- 
inder being  about  %  inch  smaller  in  diameter  than  the 
box.  If  the  box  is  large,  a  piece  of  wood  about  4  or  5 
inches  wide  and  i  inch  thick,  with  one  side  planed  ap- 
proximately to  the  curve  of  the  inside  of  the  box,  will 
be  better. 

To  form  the  ends  of  the  box  marked  A  A  in  Fig.  109, 
the  following  is  the  best  way  :  Make  two  pieces  of  wood 
4  inches  long,  2  inches  wide,  and  i  inch  thick.  Plane 
them  so  that  two  of  the  narrowest  faces  will  make  a 
good  joint  at  right  angles  to  the  wider  sides.  Now 
face  up  a  chuck  about  6  inches 
in  diameter,  and  while  it  is  re- 
volving in  the  lathe,  make  a  fine 
pencil  mark  or  dot  in  the  cen- 
ter. Place  one  of  the  pieces 
flat  on  the  chuck,  so  that  one  of 
the  face  edges  will  pass  thru 
this  dot  mark.  There  should 

also  be  a  mark  put  at  the  center  of  the  length  of  the 
corner  that  comes  in  contact  with  the  chuck ;  this  mark 
should  also  be  placed  at  the  center  so  that  the  work 
be  balanced  in  the  lathe.  Nail  it  to  the  chuck  in  this 
position,  and  then  place  the  other  piece  alongside  and 
nail  it  also.  If  this  work  is  correctly  done,  the  chuck, 
with  pieces  nailed  on,  will  look  something  like  Fig. 
114.  This  is  now  to  be  put  on  the  lathe,  and  a  hole  of 


146 


WOOD  PATTERN-MAKING 


the  shape  of  the  core-print  on  the  pattern  turned  into  it. 
If  the  blocks  have  been  properly  placed,  each  will  have 
a  semi-circular  hole  in  it,  representing  one-half  the  frus- 
trum  of  a  cone,  whose  dimensions  correspond  exactly 
with  those  of  the  core-print  on  the  pattern.  These  are 


03 

FIG.  115.  FIG.  116. 


now  to  be  taken  from  the  chuck  and  nailed  and  glued, 
one  on  each  end  of  the  body  of  the  box  previously  made. 
This  must  be  cut  to  the  exact  length  required,  which  in 
this  case  will  be  4'/4  inches.  It  is  necessary  that  a  core- 
box  for  a  vertical  core  should  be  about  ^  inch  longer 
than  the  pattern,  so  that  the  cope  of  the  mold  will  be 
sure  to  fit  tightly  around  the  core  ;  then  no  metal  can 
flow  up  alongside  of  it  and  over  the  end  of  the  core, 


TYPICAL  PATTERNS  147 

thus  covering  up  the  vent  and  causing  the  casting  to 
blow.  For  the  above  reason  all  vertical  cylindrical 
cores  should  be  %  inch  longer  than  the  total  length  of 
the  pattern  and  prints.  To  complete  the  box  it  is  only 
necessary  to  nail  pieces  B  B,  Fig.  ioy,  one  on  each  end, 
and  then  give  a  taper  at  the  point  C,  Fig.  109.  To  make 
tne  core  two  halves  are  made  in  this  box ;  after  dry- 
ing, they  are  pasted  together,  making  a  complete  core. 


The  next  example  is  very  similar  to  the  former  one, 
but,  having  a  flange  at  both  ends,  it  will  have  to  be 
molded  horizontally,  and  will  therefore  require  a  hori- 
zontal core.  The  completed  casting  is  represented 
by  Fig.  115,  and  a  pattern  for  producing  it  by  Fig.  116. 
On  account  of  the  shape  of  this  casting  it  will  be  best 
to  make  the  pattern  a  parted  pattern.  This  will  save 
the  molder  some  time  and  work,  as  it  will  give 
a  form  that  is  easily  removed  from  the  sand.  In 
making  this  pattern,  the  first  thing  to  do  will  be  to  get 
two  pieces  of  wood  of  such  dimensions  that  when  they 
are  put  together  the  pattern  can  be  turned  out  of  them. 
As  will  be  noticed  by  the  drawing,  there  is  no  finish 
required  except  on  the  face  of  the  flanges.  Allowing 
for  finish,  the  length  of  the  pattern  without  the  core 
prints  will  be  6I/\.  inches.  The  core  is  to  be  il/2  inches 
in  diameter,  so  the  prints  will  be  il/2  inches  long;  then 
2  inches  more  must  be  added  for  fastening  together 
at  the  ends,  making  a  total  of  n*4  inches  for  rough  size. 
Two  pieces,  then,  are  needed,  1 1%  inches  long,  4  inches 
wide,  and  2  inches  thick.  The  next  step  will  be  to  plane 


148  WOOD  PATTERN-MAKING 

one  of  the  larger  sides  of  each  piece  to  a  true  surface, 
to  form  a  joint  between  them. 

The  next  thing  is  to  locate  the  holes  for  the  pattern 
pins,  so  that  no  mistake  will  be  made  in  putting  to- 
gether the  two  parts  of  the  pattern  after  being  sep- 
arated. The  most  practical  way  to  do  this  is  as  follows : 
On  the  plane  surface  of  one  of  the  pieces  locate  these 
holes  with  a  pencil  mark ;  these  marks  to  be,  say  4  and  5 
inches,  respectively,  from  the  center  of  its  length  and 
approximately  on  the  center  of  its  width.  If  the  pins 
are  thus  located,  the  molder  will  not  err  in  putting  the 
two  halves  together,  for  if  he  happens  to  do  it  incor- 
rectly, he  will  at  once  recognize  his  mistake. 

Having  marked  the  points  where  it  is  desired  to  put 
the  pins,  take  two  small  brads  and  lay  them  on  the 
block  with  the  heads  at  these  points ;  now  carefully  lay 
the  other  pieces  on  these  brads,  and,  having  brought  it 
into  exactly  the  desired  position,  strike  the  top  piece  a 
light  blow  with  the  hammer  or  mallet.  This  will  cause 
the  heads  of  the  brads  to  make  corresponding  impres- 
sions on  both  blocks.  At  these  impressions,  bore  holes 
l/2  inch  deep.  The  diameter  of  the  hole  is  of  small 
moment;  for  patterns  of  this  size,  *4  mcri  i§  about 
right ;  the  larger  the  work,  the  larger  the  pins  should  be. 

The  next  thing  to  be  done  will  be  to  make  the  pins, 
for  which  a  piece  about  10  inches  long  will  be  found 
the  best.  Select  a  piece  that  is  straight  in  the  grain, 
and  rip  to  such  a  size  that  one  side  of  the  square  stick 
equals  the  diameter  of  the  hole  plus  ^  of  an  inch.  With 
the  jack-plane  plane  this  into  an  octagonal  form.  Then, 
grasping  one  end  in  the  left  hand  and  laying  the  other 


TYPICAL  PATTERNS  149 

end  on  the  bench,  with  the  block-plane  plane  off  the 
corners,  making  it  as  nearly  round  as  possible  for 
about  3  inches  of  its  length.  This  round  part  should 
be  made  to  fit  the  hole  exactly — that  is,  at  the  extreme 
end.  With  knife  and  sandpaper,  or  file,  round  this  end 
to  an  approximately  parabolic  form.  Now  set  it  into 
the  hole  in  the  piece  into  which  the  pins  are  not  to  be 
fastened,  far  enough  so  that  it  exactly  fits  the  hole. 
Make  a  pencil  mark  part  way  around  it  right  at  the  sur- 
face of  the  block.  Now  measure  the  depth  of  the  hole 
into  which  the  pin  is  to  be  fastened,  and  mark  this 
distance  along  the  pin  from  the  mark  previously  made. 
This  is  the  point  at  which  to  saw  the  pin  off.  Now,  if 
this  pin  be  driven  down  into  the  hole  clear  to  the  bot- 
tom, the  first  mark  will  come  even  with  the  parting 
and  will  exactly  fit.  By  means  of  these  pins,  the  two 
parts,  after  being  separated,  may  be  brought  together 
again  in  exactly  the  same  relative  position,  and  will 
be  held  firmly  so  that  they  will  not  slide  or  shift  side- 
wise  during  the  process  of  molding.  They  should  be 
loose  enough  so  that  the  pattern  will  fall  apart  of  its 
own  weight,  but  still  not  loose  enough  so  that  there 
is  any  perceptible  movement  sidewise. 

When  both  pins  are  in  place,  the  blocks  are  ready  to 
be  fastened  together.  There  are  three  ways  in  which 
this  may  be  done.  If  there  is  time  to  wait  for  glue  to 
dry,  the  best  way  is  to  put  glue  on  the  ends  of  each  piece 
fora  distance  of  about  YZ  inch,  and  clamp  them  together 
with  a  handscrew  or  other  clamp.  If  it  is  desired  not  to 
wait  for  the  glue,  then  a  screw  may  be  put  through  the 
ends,  fastening  them  together  in  that  way.  It  is  advis- 


150  WOOD  PATTERN-MAKING 

able,  for  convenience  in  turning,  to  use  a  short  screw, 
deeply  countersinking  its  head.  For  a  piece  of  this  size 
a  i^4  incn  No.  14  screw  may  be  used.  If  care  is  taken 
to  have  one-half  the  length  of  the  screw  in  each  piece, 
it  can  be  turned  to  the  required  size  of  the  print,  out 
to  the  extreme  end.  The  third  method  is  to  clamp  them 
together  with  "dogs,"  which  are  small  square  staples 
made  for  the  purpose.  When  the  pieces  are  thus  fas- 
tened together,  they  are  ready  to  be  placed  in  the  lathe 


FIG.  117. 

and  turned.  This  may  be  done  practically  in  the  same 
way  as  in  the  previous  example.  For  a  piece  of  this 
size  it  is  advisable  to  cut  off  the  corners  of  the  block 
before  mounting  it  in  the  lathe ;  this  may  be  done  with 
a  hand  axe  or  mallet  and  chisel.  One  must  allow  for 
draft,  and  also  for  finish  on  the  faces  of  the  flanges, 
making  these  faces,  and  the  ends  of  the  prints,  convex 
as  shown  in  Fig.  116. 

The  next  thing  to  make  will  be  the  core-box.  As  this 
pattern  requires  what  is  known  as  a  plain,  cylindrical, 
horizontal  core,  and  is  therefore  symmetrical,  only  a 
half-box  is  needed.  But  if  it  is  desired  to  reduce  the 
cost  in  the  foundry,  a  core-box  like  the  one  represented 


TYPICAL  PATTERNS  151 

by  Fig.  79,  page  109,  in  the  chapter  on  cores,  would  be 
used,  the  core  being  made  complete  at  one  operation. 
The  half-box  would  be  made  as  directed  for  the  straight 
part  of  the  core-box  in  the  last  example,  with  end 
pieces,  as  represented  by  Fig.  117.  If  a  whole  box  is 
made,  then  the  block  would  need  to  be  twice  as  long, 
and  worked  out  as  in  Figs.  109  and  no.  After  this  is 
worked  out,  it  should  be  cut  in  two  pieces  and  pinned 
together  in  the  same  way  as  was  done  with  the  two 
pieces  for  the  pattern.  One  way  of  doing  this  that  is 
quite  practical  is  the  following:  After  cutting  the 
pieces  the  correct  length,  place  them  together  in  their 
proper  rdlation  to  each  other ;  fasten  them  in  the  vise 
in  a  vertical  position,  with  one  end  above  the  bench  top, 
and  bore  a  hole  of  the  size  required  for  the  pin  clear 
through  the  first  piece  and  about  half  an  inch  into 
the  other.  Now  by  putting  the  pin  through  the  hole, 
it  will  be  filled  and  make  an  accurate  and  workmanlike 
job.  If  brass  pins  are  used,  this  could  not  be  done, 
because  the  pin  would  not  fill  the  hole;  and  as  the  pin 
and  its  tube  are  of  a  different  size,  the  hole  could  not 
be  bored  with  the  same  bit.  The  inside  length  of  this 
core  box  should  be  ^  inch  shorter  than  the  total  length 
of  the  pattern  and  prints,  so  that  the  core  may  be  more 
easilv  set  into  the  mold. 


The  next  example  to  be  taken  up  is  typical  of  a  quite 
large  class  of  pattern  work,  generally  known  as  plate 
work.  It  is  usually  comparatively  thin  in  cross-section 
in  at  least  one  direction.  This  class  of  work  includes 


152  WOOD  PATTERN-MAKING 

shafting  hangers  of  different  patterns,  some  kinds  of 
small  pump  standards,  and  any  kind  of  work  that  is 
composed  of  two  webs  running  into  or  crossing  each 
other.  This  last  is  illustrated  by  Fig.  118.  The  ex- 
ample to  be  used  to  demonstrate  the  methods  usually 
followed  in  building  patterns  of  this  type  is  repre- 
sented by  Figs.  118  and  119.  In  order  to  make  the  best 
pattern  for  durability  and  permanence  of  form,  the 
foundation  should  be  built  of  three  pieces,  as  shown 
in  Fig.  119,  which  is  almost  self  explanatory.  Of 
course,  this  part  of  the  pattern  could  be  built  of  one 
piece  of  board,  but  it  would  be  very  weak  through  the 
portion  marked  A.  By  building  it  as  represented,  two 
things  are  gained :  it  is  uniformly  strong  throughout, 
and  smaller  pieces  of  wood  may  be  used.  As  in  the 
case  of  all  other  patterns,  so  in  this,  it  should  be  first 
determined  how  the  pattern  is  to  be  withdrawn  from 
the  mold.  It  will  soon  be  seen  that  the  best  way  will 
be  to  have  the  face  marked  B,  Fig.  118,  down  in  the 
nowel ;  thus  there  will  be  left  an  almost  flat  surface 
for  the  molder's  parting,  which  will  then  occur  along 
line  C  D.  It  will,  of  course,  be  necessary  to  make  part 
E  loose,  so  it  will  lift  with  the  cope  sand.  This  is  a 
type  of  what  is  known  as  loose  pieces  molded  in  the 
cope  and  drawn  therefrom  after  it  is  lifted  off  from  the 
nowel.  The  method  now  to  be  described  of  laying  out 
and  building  this  pattern,  may  be  used  in  building 
any  pattern  of  this  general  type ;  modifications  of  it 
may  be  introduced  when  needed. 

The  first  step  to  be  taken  in  making  this  pattern  is 
the  making  of  two  pieces  of  board  about  15  inches  long 


TYPICAL  PATTERNS 


153 


FIG.  118. 


154  WOOD  PATTERN-MAKING 

by  3  inches  wide  and  y$  inch  thick,  and  one  piece  about 
9  inches  long,  4  inches  wide  and  ^s  inch  thick.  These 
must  be  planed  on  one  side  to  a  true  plane,  with  the 
edges  straight  and  at  right  angles  to  the  side ;  a  face 
mark  should  be  put  on  each  piece.  Now  the  two  long 
pieces  should  be  cut  to  shape,  so  as  to  make  a  good 
joint  at  F,  Fig.  119,  care  being  taken  that  the  two 
lower  corners  are  far  enough  apart  to  include  all  of  the 
pattern  at  that  end.  Tack  these  to  the  bench  or  laying- 
out  table  in  their  proper  position  with  relation  to  each 
other;  then  locate  points  G  H,  and  lay  the  third  piece 
on  the  others  with  its  edge  at  these  points,  and  make 
knife  marks  against  this  and  across  the  two  pieces. 
Now,  without  moving  the  third  piece,  make  marks 
on  it  with  the  point  of  the  knife  at  the  points  K,  L, 
M,  and  N ;  connect  these  points  with  good,  clean  knife 
marks  across  the  face;  then  finish  the  laying-out  by 
making  gage  marks  in  the  center  of  the  edges  where 
needed  to  limit  depth  of  gains;  now  cut  the  gains  to 
these  lines.  Then  cut  out  the  ends  of  the  short  piece 
to  the  same  thickness,  but  on  the  opposite  side ;  fit 
them  together  and  glue  them  and  put  them  in  clamps 
till  dry. 

While  this  is  drying,  a  piece  of  board  about  15  inches 
long,  6  inches  wide,  and  Y*  inch  thick,  can  be  gotten  out. 
Out  of  this  can  be  sawn  pieces  for  making  the  curved 
pieces  that  are  built  on  to  form  the  raised  portions 
that  are  to  be  glued  on  to  the  main  piece.  These  should 
be  cut  from  the  board  so  that  the  grain  of  the  wood  will 
run  parallel  with  a  chord  of  the  curve,  making  the 
segment  not  to  exceed  one-quarter  of  the  circumfer- 


TYPICAL  PATTERNS 


155 


FIG.  119. 


156  WOOD  PATTERN-MAKING 

ence  of  the  circle.  If  they  are  made  longer  than  this, 
there  will  be  too  much  end  grain.  The  straight  pieces 
may  also  be  gotten  out  at  this  time,  so  they  will  be 
ready  when  wanted. 

When  the  glue  is  dry  on  the  three  pieces  that  to- 
gether form  an  A-shaped  piece,  it  is  to  be  planed  on 
both  sides  to  true  planes  until  it  is  >2  inch  thick.  It 
is  now  ready  to  have  the  lines  laid  out  on  it  as  shown 
by  Fig.  119.  In  laying  out  these  dimensions,  the  shrink 
rule  should  be  used,  as  that  will  allow  for  the  shrinkage 
of  the  metal  in  the  casting.  After  these  are  all  laid 
out,  i,t  may  be  sawn  out  on  the  band  and  jig  saws.  In 
doing  this  sawing,  it  is  best  to  cut  just  outside  the  line, 
so  that  in  filing  and  finishing  the  edges,  the  marks  may 
serve  as  a  guide.  It  is  now  ready  to  have  pieces  set 
on  to  form  the  projecting  webs,  which  may  be  cut  from 
the  ^2-inch  piece  already  mentioned.  It  will  be  best 
to  commence  at  the  top  of  the  pattern. 

The  first  will  be  a  solid  piece  extending  all  over  the 
upper  end  down  to  and  including  the  semi-circle  that 
joins  the  long  outside  webs.  After  this  the  other 
circular  parts  may  be  cut  out  and  put  on.  Now  the 
pieces  to  form  the  feet  may  be  made  and  glued  in  place  ; 
then  the  straight  pieces  should  be  nicely  fitted  to  these 
and  glued  in  place.  Now  a  piece  of  wood  may  be 
gotten  out  to  form  the  fillet  around  the  bearing,  or  top 
part  of  the  pattern,  where  it  joins  the  main  part  of 
the  pattern.  This  should  be  about  Y*  inch  thick,  and 
should  be  large  enough  to  extend  H  inch  all  round  out- 
side the  bearing.  For  convenience  in  cutting  out  the  fil- 
let, it  is  best  to  let  the  grain  of  the  wood  in  this  piece 


TYPICAL  PATTERNS  157 

run  parallel  with  the  outside  line  of  the  pattern  at  this 
point.  A  piece  is  also  needed  to  go  on  the  other  side 
to  form  a  fillet  on  which  to  pin  the  loose  piece,  E,  Fig. 
118.  Now  a  piece  to  form  the  bearing  itself  may  be 
made.  As  this  is  required  to  be  more  than  a  half  circle, 
it  will  be  best  to  make  it  with  the  planes.  According 
to  the  dimensions  given,  it  will  need  to  be  of  the  fol- 
lowing finished  measurements :  about  4  inches  long, 
zl/4  inches  wide,  and  i^$  inches  thick.  It  should  be 
planed  square  to  these  dimensions,  and  a  semi-circle 
described  on  each  end,  and  then  planed  and  sand- 
papered down  to  it.  A  piece  can  now  be  cut  from  this 
just  2  inches  long,  and  fastened  on  top  of  the  ^  inch 
fillet  piece.  Both  ends  of  this  piece  must  be  square, 
so  it  will  set  in  vertical  position  on  one  end,  and  so  the 
core-print  to  be  made  later  will  fit  well.  A  piece  of 
this  is  required  for  the  other  or  cope  side  i  inch  long. 
This,  however,  will  not  be  fastened  in  place  perma- 
nently, but  will  be  pinned  on  so  that  it  will  lift  with  the 
cope  sand  when  the  cope  is  lifted  off.  The  best  way 
to  do  this  is  to  place  it  in  a  correct  position  and  drive 
two  small  brads  through  it,  taking  care  not  to  put  them 
where  the  pin  holes  are  to  be  bored.  Now,  with  brace 
and  bit,  bore  two  holes  clear  through  it  and  into  the 
other  part  of  pattern  to  a  depth  of  about  l/2  inch.  A 
%-mch  auger  bit  is  a  good  size  to  use  for  this  purpose. 
Now  make  pins  as  directed  for  use  in  the  parted  pat- 
tern on  page  149.  In  this  case  they  can  be  put  through 
and  fill  the  holes,  as  they  will  have  to  be  on  the  loose 
piece. 

The    next   thing   will   be   to   make    the    core-prints. 


158 


WOOD  PATTERN-MAKING 


These  will  extend  the  whole  length  of  the  bearing, 
and  of  course  the  length  of  the  prints  besides,  and  as 
this  is  a  vertical  core,  will  project  i  inch  beyond  the 
pattern  on  each  side.  To  make  these  prints  for  this 
particular  job,  take  a  piece  of  wood  about  7  inches  long 
and  il/2  inches  square,  place  it  in  the  lathe  and  turn 
to  shape  and  dimensions  as  shown  by  Fig.  120.  The 


FIG.  120. 


shaded  portion  will  be  cut  out  so  it  will  fit  down  on  to 
the  pattern  already  made.  The  line  just  above  the 
shaded  part  is  the  point  to  cut  through  so  as  to  co- 
incide with  the  pattern  parting. 

To  complete  this  problem  a  core-box  will  be  needed, 
which  will  be  made  as  shown  at  Fig.  121.  The  pro- 
cess is  the  same  as  already  described,  except  as  to 
pieces  marked  X.  These  are  to  form  a  crease  or 
groove  in  the  core,  to  form  the  babbitt  pieces  on  the 
casting  shown  at  O,  Fig.  118.  These  are  simply  pieces 
of  wood  l/%  inch  thick,  of  a  size  equal  to  the  cross- 
section  of  the  core-box,  and  with  a  semi-circle  cut  in 
on  one  side,  whose  diameter  is  I  inch,  as  that  is  the  size 
of  the  shaft  the  bearing  is  intended  to  carry.  In  build- 
ing the  box,  the  pieces  must  be  nailed  in  between  the 
body  of  the  box  and  the  parts  forming  the  prints.  The 
completed  box  is  shown  in  Fig.  121. 


TYPICAL  PATTERNS 


159 


The  pattern  for  a  hook  lever  for  Corliss  valve  gear 
will  be  the  next  problem  taken  up.  This  gives  a  good 
example  of  what  is  known  in  the  foundry  as  an  irreg- 
ular parting,  and  is  illustrated  in  the  chapter  on  mold- 
ers'  joints  by  Fig.  87,  the  molders'  parting  following 
the  heavy  broken  line.  It  is  also  a  good  example  of 
what  may  be  called  a  built-up  solid,  one-piece  pattern, 


FIG.  121. 


meaning  that  the  completed  pattern  has  no  parting. 
This  is  typical  of  a  very  large  class  of  patterns,  as  all 
patterns  would  be  made  one-piece  if  they  could  be 
conveniently  molded  in  that  shape.  Before  commenc- 
ing the  actual  work  on  this  pattern,  notice  particularly 
the  position  of  the  molders'  parting,  and  then  the  direc- 
tion of  the  required  draft.  The  first  pieces  to  be  gotten 
out  will  be  the  two  of  which  to  make  the  arms,  each 
about  4^2  inches  wide,  10  inches  long  and  y±  inch  thick. 
These  should  be  planed  to  a  true  surface  on  both  sides  to 
the  exact  thickness,  y^  inch,  then  nailed  together  so 
that  their  lines  will  be  at  the  required  angle  of  105  de- 


160 


WOOD  PATTERN-MAKING 


grees.  On  one  surface  of  these  lay  out  the  shape  ac- 
curately as  indicated  by  the  drawing,  allowing  about  ^ 
inch  for  draft  around  the  central  boss.  The  arms  may 
now  be  sawn  out  on  the  band-saw,  leaving  the  marks  as 
a  guide  for  finishing  with  a  file.  The  round  boss  or  disk 


A,  Fig.  122,  may  now  be  made.  This  should  be  sawn 
out  about  4^4  inches  in  diameter,  i^4  inches  plus  y% 
inch  for  "finish"  in  thickness,  and  mounted  on  the  lathe 
and  turned  to  exact  dimensions,  which  are  4  inches  in 
diameter  at  B  and  4TV  inches  at  C,  Fig.  123.  Another 
boss  is  needed  at  D,  Fig.  122,  but  only  ^  inch  thick. 
These  may  now  be  nailed  in  place  on  the  arms,  care 
being  taken  as  to  the  side  on  which  each  is  put,  as  the 
position  of  these  pieces  will  determine  whether  the 


TYPICAL  PATTERNS 


161 


1 


162  WOOD  PATTERN-MAKING 

pattern  is  to  be  a  right  or  left  hand  lever.  This  can  be 
easily  settled  by  comparing  the  work  already  done 
with  the  drawing.  A  screw  chuck  affords  a  good 
means  for  holding  these  pieces  in  the  lathe,  to  turn 
the  four  bosses  required  for  the  ends  of  the  arms. 
These  four  may  all  be  turned  out  of  one  piece  by  cut- 
ting off  a  piece  from  a  two-inch  plank  about  2  inches 
long,  measured  in  the  direction  of  the  grain,  and  6 
inches  long,  across  the  grain,  and  mounting  it  in  the 
lathe  so  that  the  grain  is  perpendicular  to  the  axis  of 
the  lathe.  This  is  plainly  shown  by  Fig.  122.  After 
these  bosses  are  all  fastened  in  place  (they  should  be 
so  placed  that  the  grain  will  run  in  the  same  direction 
as  it  does  in  the  arms),  the  arms  may  be  shaped  or 
rounded  into  the  elliptical  form  indicated  at  L,  Fig. 
123,  and  all  the  different  surfaces  blended  into  each 
other  so  as  to  make  one  even  and  well-molded  surface. 
The  central  hole,  or  bore,  as  it  is  sometimes  called, 
will  of  course  be  made  with  a  dry-sand  core,  so  that  it 
will  be  necessary  to  use  core-prints  and  a  core-box. 
This  being  a  vertical  core,  the  shape  of  the  prints  and 
the  core-box  will  be  the  same  as  for  the  first  exercise, 
Fig.  109.  For  the  convenience  of  the  molder  the  top 
print  B  should  be  left  loose. 


CHAPTER  XIV 
PULLEY  PATTERNS 

The  next  type  of  pattern  work  to  be  considered  is 
the  making  of  patterns  of  the  general  shape  of  Fig.  102, 
sometimes  called  annular  patterns.  The  example  used 
for  the  purpose  of  explaining  how  such  work  is  done 
is  the  pattern  for  an  8-inch  pulley  with  a  3-inch  face. 
The  technical  description  for  shop  use  is  written  like 
this  :  Pulley  8"x3",  hub  2j4",  four  arms,  rim  Ty  thick. 
The  "8""  refers  to  the  outside  diameter  of  the  pulley ; 
the  "3""  to  the  width  of  face;  "2^4""  to  the  diameter 
of  the  hub  or  central  boss,  through  which  the  shaft 
runs ;  and  "four  arms"  to  the  radial  arms  or  spokes 
that  connect  this  central  boss  with  the  rim  of  the 
pulley ;  the  "-£%"  rim"  refers  to  the  thickness  of  the  rim 
at  its  outer  edge.  The  finished  pulley  is  represented 
by  Fig.  124. 

The  first  step  in  this  pattern  as  of  all  others,  is  to 
determine  how  it  is  to  be  molded.  As  to  mold  it  from 
a  one-piece  pattern  would  be  quite  difficult,  it  is  best  to 
make  a  parted  pattern,  the  parting  being  made  on  a 
central  plane  running  through  the  center  of  the  arms ; 
this  means  that  two  halves  will  be  made.  The  first 
thing  to  do  is  to  prepare  a  chuck  about  9  inches  or 
f)l/2  inches  in  diameter  and  about  i  inch  thick,  and  face 
it  off  true.  On  this  chuck  build  up  a  ring  or  hollow  cyl- 
inder high  enough  so  that  both  halves  may  be  cut  from 
it.  If  enough  is  built  for  both  halves,  it  will  need  to 

163 


164  WOOD  PATTERN-MAKING 

be  3  inches — equal  to  the  width  of  pulley  face,  plus  i 
inch  for  cutting  off,  making  in  all  4  inches  in  height. 
This  is  to  be  built  of  straight-grained  white  pine  about 
y%  inch  thick;  therefore  it  will  take  five  thicknesses 
for  the  required  height.  These  pieces  will  be  cut  into 
segments,  or  cants,  of  such  length  that  four  will  com- 
plete the  circle.  They  must  be  cut  so  that  the  grain 
of  the  wood  is  parallel  to  the  chord  of  the  curve. 
These  will  be  cut  on  the  band-saw  or  jig-saw,  and  made 
large  enough  so  that  the  ring  may  be  turned  and 
still  allow  for  draft  and  finish.  As  ^  mcn  is  to  be 
allowed  for  draft  and  l/&  inch  for  finish,  and  as  the 
finished  pattern  will  need  to  be  8^  inches  in  diameter 
at  the  center,  the  rough,  built-up  ring  should  be  about 
8^4  inches  in  diameter.  For  a  guide  in  building,  make 
a  pencil  mark  on  the  chuck  while  it  revolves  in  the 
lathe,  so  that  the  circle  thus  made  will  be  of  the  re- 
quired diameter.  To  mark  out  the  segments,  proceed 
as  follows :  Set  the  dividers  at  the  radius  required, 
4^  inches,  and  describe  an  arc  tangent  to  the  edge 
of  the  board  farthest  from  you,  from  which  it  is  pro- 
posed to  cut  the  cants.  Set  the  dividers  to  3/^  inches, 
and  describe  another  arc  concentric  with  the  first  one ; 
this  will  leave  the  cants  Y^  inch  wide ;  lay  a  framing- 
square  on  the  board  at  an  angle  of  45  degrees  with  its 
edge,  with  the  heel  exactly  over  the  center  from  which 
the  arcs  were  struck ;  and  at  the  points  where  the 
sides  of  the  square  cross  the  arcs,  make  marks. 
This  will  give  the  length  of  the  required  segment  and 
at  the  same  time  give  the  radial  line  which  is  the 
correct  line  for  cutting  the  ends  of  the  cants.  If  the 
board  is  too  long  to  carry  to  the  band-saw  conveniently. 


PULLEY  PATTERNS 


165 


166 


WOOD  PATTERN-MAKING 


cut  off  with  the  handsaw  a  piece  just  long  enough 
for  the  segment.  Saw  out  this  one  segment,  using  it 
as  a  pattern  with  which  to  mark  out  all  the  other 
nineteen  cants  required.  This  pattern  segment  should 
be  cut  out  so  that  it  will  be  a  little  too  long;  then  the 
others,  when  marked  out  by  it,  may  be  cut  to  the 
mark  and  still  be  long  enough  to  allow  for  fitting,  as 


FIG.  125. 

the  joints  must  be  exact.  Now  saw  out  four  more 
and  then  proceed  to  fasten  them  on  the  chuck.  The 
others  may  be  sawn  out  while  the  glue  is  drying.  A 
trimmer  or  shoot-board  will  be  needed  on  which  to 
shoot  or  plane  the  ends  of  the  pieces.  The  shoot- 
board  and  the  method  of  its  use  are  shown  in  Fig.  125. 
The  trimmer  is  a  more  complicated  machine  and  is 


PULLEY  PATTERNS  167 

represented  in  the  frontispiece.  Plane  or  trim  both 
ends  of  one  of  the  segments  and  drive  a  2-inch  brad 
into  it  at  each  end  from  the  top  side  almost  through 
it ;  put  some  glue  on  the  ends  and  on  the  under  side, 
and  place  it  on  the  chuck  just  inside  the  circle  already 
made,  driving  the  brads  down  until  the  heads  protrude 
just  far  enough  so  that  they  may  afterwards  be  with- 
drawn with  the  claw-hammer.  Now  fit  another  seg- 
ment up  to  this  one,  being  sure  that  it  makes  a  good 
joint,  especially  on  the  inside  of  the  ring,  for  if  the 
joint  is  not  good  the  small  triangular  pieces  formed 
in  cutting  the  segments  will  be  torn  out  by  the  chisel 
during  the  process  of  turning.  The  second  piece  may 
now  be  glued  into  place,  being  sure  as  before  to  put 
glue  on  both  ends  and  also  on  the  end  of  the  piece 
that  is  in  place.  Thus  the  ends  of  the  pieces  are  glued 
twice,  which  is  very  necessar}'  if  a  strong  joint  is 
wanted.  This  is  called  sizing  the  joint.  If  it  is  not 
done,  the  first  coat  of  glue  will  be  absorbed  by  the 
wood  and  the  joint  will  be  weak.  This  course  may  be 
followed  until  the  first  ring  or  layer  of  segments  is 
complete,  when  it  should  be  allowed  to  dry.  After  the 
glue  is  dry,  the  brads  may  be  pulled  out  and  the  chuck 
put  in  the  lathe  and  the  ring  faced  off,  making  it  true 
in  both  directions.  The  next  layer  may  now  be  put 
on  in  the  same  way.  The  ends  of  the  cants  should  be 
placed  about  in  the  center  of  those  in  the  lower  layer 
so  as  to  break  joints. 

The  above  is  the  method  usually  followed  in  making 
this  form  of  pattern  when  the  cross-section  of  the  ring 
is  small — that  is,  of  ^4  inch,  or  less.  If  the  ring  is 
to  be  i  inch  or  more  thick,  it  is  best  to  use  hand-screws 


168  WOOD  PATTERN-MAKING 

to  hold  the  different  layers  down  until  the  glue  is  dry. 
If  simply  a  ring  is  wanted  that  is  I  inch  or  more  in 
thickness,  and  we  are  sure  there  is  no  cutting  to  be 
done  on  it  in  the  future,  then  the  brads  may  be  driven 
clear  in  and  left  in  the  work,  except  in  the  first  layer. 
This  will,  of  course,  obviate  the  waiting  for  the  glue 
to  dry,  so  that  a  ring  may  be  built  up  very  rapidly. 
Zinc  nails  or  wooden  pegs  may  also  be  used  in  this 


FIG.  126. 

class  of  work,  but  if  a  good  quality  of  glue  is  used, 
they  are  not  necessary.  The  work  is  now  ready  for 
the  lathe.  It  is  advisable  before  turning  it  to  glue  up  the 
stuff  for  the  arms  and  hub ;  then  we  need  not  wait  for 
the  glue  to  dry,  as  it  will  dry  by  the  time  the  rim  is 
turned,  unless  this  is  done  much  more  quickly  than 
it  usually  is. 

There  are  two  general  ways  of  building  up  the  spider, 
as  it  is  sometimes  called,  of  a  pulley;  which  is  the 
better  way  is  determined  by  the  size,  number  of  arms, 
and  some  other  things.  One  way  is  what  is  known 


PULLEY  PATTERNS  169 

as  checking  the  arms  together,  and  then  gluing  the 
boss  on  afterwards.  This  is  a  good  way,  if  care  is 
taken  so  that  they  fit  exactly.  If  they  are  made  too 
tight,  however,  the  ends  are  likely  to  be  bent  out  of 
the  correct  position  by  the  springing  of  the  timber. 
This  method,  of  course,  cannot  be  used  for  spiders 
having  an  odd  number  of  arms.  A  better  way  for  most 
work  is  to  miter  the  arms  together.  The  only  objec- 
tion to  this  method  is  that  it  is  comparatively  weak. 
But  this  defect  is  easily  overcome ;  for,  if  there  is  no 
hub  or  boss  required,  a  recess  may  be  turned  into  the 
arms  after  they  are  glued  together,  and  a  piece  of  hard- 
wood, or  metal,  set  in  and  a  screw  put  into  each  arm, 
as  shown  in  Fig.  126.  If  a  hub  is  wanted,  and  it  usually 
is,  this  will  give  the  required  strength.  This  method 
may  be  used  for  spiders  of  any  number  of  arms. 

To  make  the  spider,  then,  for  this  pattern  and  in  the 
last  mentioned  way,  the  first  thing  to  do  is  to  get  out 
eight  pieces,  4^2  inches  long,  2  inches  wide,  and  about 
-fg  inch  thick ;  cut  one  end  of  each  piece  so  as  to  make 
an  angle  of  90  degrees  at  an  angle  of  135  degrees  to 
each  edge.  Now  saw  out  on  the  band-saw,  or  jig-saw, 
two  disks  about  3  inches  in  diameter,  and  1%  inches 
thick,  and  glue  four  of  the  thin  pieces  on  to  each  disk, 
with  the  point  of  the  QO-degree  angle  directly  in  the 
center.  The  best  way  to  do  this  is  to  start  three  i-inch 
brads,  one  in  each  corner  of  each  of  the  triangles ;  put 
on  some  glue,  lay  the  piece  in  place  and  drive  the  nails 
down,  leaving  the  heads  projecting  so  the  brads  may 
be  afterwards  withdrawn  with  the  claw-hammer  or 
pincers.  Now  these  may  be  set  aside  to  allow  the  glue 
to  dry.  The  way  these  five  pieces  will  appear  after 


170 


WOOD  PATTERN-MAKING 


being  glued  together  is  shown  by  Fig.  127.  While 
these  are  drying,  the  chuck,  with  the  built-up  rim  on 
it,  may  be  put  in  the  lathe  and  the  rim  turned  to  size. 
The  extreme  outside  diameter  should  be  8^  inches. 
This  is  at  the  central  plane  through  the  hollow  cyl- 
inder. At  the  ends  of  the  hollow  cylinder,  or  rim,  that 
is  at  the  point  where  it  is  glued  to  the  chuck,  and  the 


FIG.  127. 


opposite  or  outer  end,  the  diameter  should  be  8^4 
inches.  These  measurements  must  be  made  with  the 
shrink  rule.  Before  starting  the  lathe,  see  to  it  that  it 
will  not  run  too  fast.  The  work  to  be  turned  should 
run  at  a  surface  velocity  of  from  1200  to  1400  feet  per 
minute  for  pine  wood.  This  will  also  give  very  satis- 
factory results  on  all  ordinary  soft  wood.  If  the  wood 
is  unduly  soft,  a  higher  speed  may  be  required.  It 
may  run  much  faster  than  this  with  safety,  but  it  is 
best  to  keep  the  speed  down  as  low  as  may  be  and  still 
do  good  work.  The  work  in  hand  should  be  run  com- 
paratively slow  at  first,  so  as  to  turn  off  any  inequali- 
ties of  building,  both  on  the  inside  and  outside ;  as  the 


PULLEY  PATTERNS  171 

work  becomes  cylindrical  in  form,  a  higher  rate  of 
speed  may  be  used.  The  inside  had  better  be  turned 
first,  and  a  diamond-pointed  tool  will  be  the  best  to 
rough  it  out  with,  using  a  regular  scraper  for  the  fin- 
ishing. The  size  inside  at  the  center  will  be  7}4 
inches  in  diameter,  at  the  two  ends  75^5  inches  in  di- 
ameter. Finish  the  outer  end  back  to  a  short  distance 
beyond  the  center;  in  other  words,  back  far  enough  to 
make  a  little  more  than  one-half  of  the  rim,  which  will 
be  i^i  inches. 

When  it  has  been  turned  as  suggested,  it  is  ready 
to  be  cut  off.  Locate  the  cutting-off  point  by  holding 
a  pencil  exactly  1^5  inches  from  the  edge,  while  it  is 
revolving;  this  will  make  a  mark  at  the  proper  point. 
Now  take  a  parting  tool,  and  cut  into  the  work  just 
outside  this  mark  and  almost  through,  leaving  a  very 
thin  section  which  may  be  cut  through  with  a  knife. 
It  is  not  good  practice  to  cut  clear  through,  for  the 
work  may  fall  on  the  floor,  receiving  more  damage 
than  can  be  repaired  in  the  time  it  takes  to  cut  it  off 
with  a  knife.  If  the  work  has  been  done  correctly,  we 
have  one-half  of  the  required  rim.  As  for  the  other 
half,  it  is  already  turned  to  size  at  the  outer  end,  and  all 
that  needs  to  be  done  is  to  turn  the  rest  of  it  to  the  size 
and  shape  of  the  first  one. 

Before  being  cut  off,  both  of  these  halves  should  be 
thoroughly  sandpapered,  first  with  coarse,  and  then 
with  finer ;  No.  2  for  the  coarse,  and  No.  i  for  the  fine 
are  the  best  numbers  to  use.  As  soon  as  they  are  taken 
from  the  lathe,  it  is  well  to  give  the  rims  a  good  coat 
of  black  varnish ;  this  will  prevent,  to  a  degree,  their 
tendency  to  warp  out  of  shape. 


172  WOOD  PATTERN-MAKING 

The  spiders  are  probably  dry  by  this  time,  so  that 
work  can  be  resumed  on  them.  First,  they  must  be 
planed  to  a  perfectly  plane  surface  on  what  will  be  the 
parting  in  the  completed  pattern,  so  that  they  will 
exactly  fit  each  other.  Now  take  the  chuck  you  have 
just  used  for  turning  the  rim,  and  face  it  off  to  a  sur- 
face that  is  a  very  little  concave;  then  while  the  lathe 
is  revolving,  make  a  circle  about  the  size  of  the  disk 
in  the  spider.  Set  one-half  of  the  spider  on  the  chuck 
so  that  the  disk  coincides  with  this  circle,  and  drive  a 
brad  in  two  of  the  arms  and  into  the  chuck.  Before 
doing  this,  though,  it  is  well  to  select  two  i-inch 
screws,  and  with  brace  and  drill  bore  a  hole  through 
two  of  the  arms  just  the  size  to  fit  the  screws;  these 
holes  should  be  countersunk  for  the  head  of  the  screw, 
so  that  they  will  set  in  below  the  surface  of  the  arms, 
to  permit  of  their  being  turned  to  the  proper  thickness. 
Now  the  half  spider  may  be  set  as  suggested,  and  the 
brads  driven  far  enough  so  that  they  will  hold  the 
spider  while  the  screws  are  being  turned  in.  With  the 
scraping  tool  face  off  the  whole  thing  in  order  to  true 
up  the  faces  so  that  a  mark  can  be  made,  and  make  a 
circle  on  the  face  of  the  arms  equal  in  diameter  to  the 
outside  of  the  rim  on  the  center  of  the  pattern.  Notice 
that  this  is  where  the  arms  will  finally  be  joined  to  the 
rim.  Inside  of  this  circle  the  arms  will  be  cut  down 
to  the  required  thickness  (%.  inch),  and  to  the  required 
thickness  at  the  hub  (^  inch).  The  surface  of  the 
arms  should  be  a  straight  line  between  these  two 
points.  The  hub  can  now  be  turned  to  size  (2^4 
inches  in  diameter).  There  must  be  a  fillet  in  the 
angle  between  the  arms  and  hub  of  about  %-inch 


PULLEY  PATTERNS  173 

radius.  In  the  center  of  the  hub  turn  a  hole  about 
24  inch  in  diameter,  and  /^  inch  deep,  to  receive  a  core- 
print.  Sandpaper  the  hub  and  also  the  arms  for  a 
short  distance  from  the  hub,  taking  care  not  to  get 
your  ringers  caught  by  the  arms  as  they  swing  around. 
On  the  arms  should  be  marked  a  circle  whose  diameter 
is  the  same  as  the  inside  of  the  rim  at  the  center  of  the 
pattern.  This  circle  will  serve  two  purposes,  as  it 
furnishes  a  place  to  space  around  to  locate  the  center  of 
the  arms,  and  also  locatesthepointoftangency  between 
the  arm  and  the  fillet  that  must  be  formed  on  the  arm. 
Another  circle  should  be  made  on  the  arms  around  the 
hub;  this  may  be  about  3  inches  in  diameter;  the  exact 
size  is  not  material.  Now  this  half  may  be  removed 
and  the  other  half  put  on  and  treated  in  the  same  way, 
except  that  the  two  circles  last  mentioned  need  not  be 
made.  The  next  thing  to  do  is  to  lay  out  the  lines  for 
the  shape  of  the  arms.  First  make  a  mark  that  is 
exactly  radial  along  the  whole  length  of  one  arm,  and 
as  near  the  center  as  can  be.  Starting  from  this  line, 
by  the  use  of  the  dividers  divide  the  circle  near  the 
outer  end  of  the  arms  into  four  spaces ;  the  points  thus 
formed  will  locate  the  center  line  of  each  of  the  arms. 
Divide  the  circle  that  is  near  the  hub  in  the  same  way, 
starting  from  the  same  line.  Set  the  dividers  to  one- 
half  the  width  of  the  arms  at  these  points,  and  make 
marks  on  each  side  of  these  points ;  these  marks  will 
locate  the  sides  of  the  arms ;  now  with  a  short  straight- 
edge join  the  marks  by  a  line;  these  last  marks  will 
locate  the  sides  of  the  arms.  It  is  required  to  have 
fillets  at  the  intersection  of  the  last  made  lines  and  the 
outer  circle,  which  may  be  marked  out  by  setting  the 


174  WOOD  PATTERN-MAKING 

dividers  to  the  required  radius  (l/4  inch),  and  describ- 
ing an  arc  that  shall  be  tangent  to  the  straight  line 
and  the  circle.  Fillets  are  also  required  at  the  point 
where  the  arm  joins  the  hub ;  these  should  be  tangent 
to  a  circle  about  l/±  inch  out  from  the  hub,  and  to  both 
arms,  the  radius  to  be  such  that  one  arc  shall  touch  all 
three  points.  The  sides  of  the  part  of  the  arms  that 
are  set  into  the  rim  are  now  to  be  located  and  marked. 
This  is  done  by  making  a  mark  parallel  with  the  center 
line  of  the  arm ;  it  should  start  from  the  point  of  tan- 
gency  of  the  fillet  arc  and  the  circle  representing  the 
inside  of  the  rim,  and  should  extend  to  the  end  of  the 
arm.  All  of  the  above  marks  should  be  on  the  same 
side  as  the  hub.  The  laying  out  of  these  arms  is 
clearly  shown  by  Fig.  128.  Part  of  this  figure  shows 
one  of  the  arms  cut  to  shape  ready  to  be  set  into  the 
rim. 

Next  put  the  two  half  spiders  together  so  that  one  of 
the  hubs  shall  be  exactly  over  the  other,  or  exactly 
concentric,  and  fasten  them  temporarily  by  driving 
a  small  brad  through  two  of  the  arms.  These  brads 
had  better  be  put  as  near  the  end  of  the  arms  as  may 
be.  With  a  brace  and  TVinch  auger-bit  bore  holes  for 
pattern  pins  through  two  of  the  arms.  These  pins 
should  be  located  so  that  they  will  not  be  symmetrical 
with  the  center  of  the  pattern ;  that  is,  one  should  be 
about  3/4  inch  further  from  the  center  than  the  other, 
so  that  when  the  two  halves  are  put  together  incor- 
rectly the  error  may  readily  be  seen.  These  are  now 
ready  to  be  sawn  out,  which  can  be  done  either  on  the 
band-saw,  jig-saw,  or  with  the  key-hole  saw,  sawing 
out  one-half  at  a  time.  This  will  be  easy  to  do  in  the 


PULLEY  PATTERNS 


175 


case  of  the  first  half,  but  in  that  of  the  other,  not  so 
easy ;  for,  as  the  second  has  been  marked  from  the  first 
one,  the  marks  will  be  on  the  flat  side,  so  that  the  hub 
will  come  on  the  under  side.  To  do  the  work  more 
easily,  take  a  small  block  of  wood  with  one  dimension 


FIG.  128. 


equal  to  the  distance  that  the  hub  projects  above  the 
arms,  and  set  it  under  the  end  of  each  arm  as  it  is  being 
sawn.  It  will  be  safer  to  drive  a  brad  through  the  arm 
into  the  block,  so  that  in  moving  it  around  on  the  table 
of  the  sawing  machine  it  cannot  get  out  of  place.  If 
it  is  preferred,  both  halves  may  be  sawn  at  once ;  but 
if  this  is  done,  the  pattern  pins  should  first  be  put  in 
so  as  to  make  sure  that  the  two  halves  will  be  exactly 
alike,  and  will  set  over  each  other  just  right.  After 
these  are  sawn  out  they  must  be  filed  nicely  to  the 


176  WOOD  PATTERN-MAKING 

lines ;  then  with  knife  or  chisel  give  them  the  required 
elliptical  form  by  rounding  off  the  corners  and  blending 
in  all  the  curves  with  each  other  so  that  a  uniform 
surface  is  produced. 

The  rims  and  spiders  are  now  ready  to  be  put  to- 
gether. Lay  one  of  the  half  rims  on  the  bench  with 
the  side  up  that  will  be  the  center  of  the  pattern,  and 
lay  on  one  of  the  half  spiders.  If  everything  has  been 
done  as  directed,  they  will  .be  self-centering  because  of 
the  extra  thickness  that  was  left  on  the  end  of  the  arms 
when  turning  them.  If  this  has  not  been  done,  they 
may  be  centered  by  the  use  of  inside  calipers, 
measuring  from  the  side  of  the  rim  to  the  hub  on  three 
or  more  sides.  This  should  be  done  very  carefully, 
for  if  the  hub  is  not  in  the  center  it  will  not  look  very 
well  when  the  hole  is  bored  for  the  shaft,  and  of  course 
it  will  not  be  balanced.  When  the  spider  has  been 
correctly  located,  make  a  mark  with  a  knife  on  the  edge 
of  the  rim  on  both  sides  of  each  arm ;  before  taking 
the  spider  off  be  sure  to  mark  one  of  the  arms  and  the 
place  where  it  belongs,  so  that  it  can  be  put  back  into 
the  same  position.  Now  set  a  gage  to  the  thickness  of 
the  ends  of  the  arms,  and  gage  a  line  parallel  with  the 
edge  of  the  rim  between  the  marks  on  the  edge  for 
the  recess  for  the  arms.  Now  saw  down  to  this  gage 
mark  and  remove  the  wood,  making  a  nice  clean  gain 
exactly  to  lines.  Now  the  arms  may  be  glued  and 
nailed  in  place. 

The  other  half  should  be  treated  in  the  same  way. 
Before  marking  recesses,  lay  them  together  and  notice 
if  everything  is  coming  concentric ;  if  not,  you  can 
change  the  position  of  the  second  spider  slightly,  so 


PULLEY  PATTERNS 


177 


as  to  make  it  right.  After  getting  them  together  in 
this  way,  the  extra  length  of  the  arms  may  be  sawn 
off  and  the  parts  smoothed  up.  Two  core-prints  will 


FIG.  129. 


be  wanted  for  the  hubs ;  these,  of  course,  will  be  ta- 
pered because  the  core  will  be  vertical.  A  coat  of 
varnish  should  be  put  on  the  spider,  the  rim  having 
been  varnished  before.  The  whole  thing  is  now  ready 
to  be  finished.  First,  fill  up  with  beeswax  any  small 


178  WOOD  PATTERN-MAKING 

holes  and  any  other  defects  in  wood  or  work.  A  fillet 
is  needed  on  the  inside  of  the  rim,  on  the  side  of  each 
arm  of  both  halves.  This  can  also  be  of  wax,  put  in 
with  a  filleting  tool  of  one-half  inch  diameter.  Further 
directions  for  finishing  will  be  found  on  page  225.  To 
make  this  job  complete,  a  core-box  will  be  needed,  the 
same  as  one  described  on  page  139,  Fig.  109,  except  as 
to  dimensions. 


The  next  example  to  be  taken  up  is  typical  of  a  large 
and  interesting  class  of  patterns,  and  belongs  to  the 
general  class  known  as  parted  patterns.  One  inter- 
esting feature  of  this  example  is  the  fact  that  to  pro- 
duce the  casting,  one  core  of  each  of  the  two  general 
classes  of  cores  mentioned  in  Chapter  X,  viz.,  vertical 
and  horizontal,  are  required.  The  drawing  represent- 
ing the  casting  is  given  in  Fig.  129  and  the  drawing  of 
the  pattern  to  produce  that  casting  in  Fig.  130.  Be- 
fore starting  to  build  this  pattern  it  should  be  noticed 
that  the  pattern-maker's  parting  is  through  the  axis 
of  one  cylinder  and  the  center  of  the  length  of  the 
other,  so  that  the  central  web  will  be  parallel  with  the 
parting.  This  central  web  is  ^  inch  thick,  and  will 
be  made  of  two  pieces  •&  inch  thick,  4  inches  wide  and 
9  inches  long,  or  large  enough  so  that  the  outline  in 
the  right-hand  view  of  Fig.  130  may  be  drawn  on  them, 
with  the  exception  of  the  core-prints  of  the  larger 
cylinder.  These  two  pieces  should  be  planed  flat  and 
smooth  and  then  fastened  together  side  to  side  tem- 
porarily by  driving  two  small  brads  through  them. 
Now  lay  out  on  both  sides  of  this  double  piece  the 


PULLEY  PATTERNS 


179 


180 


WOOD  PATTERN-MAKING 


outline  as  it  appears  in  the  right-hand  view  of  Fig.  130, 
observing  to  locate  both  sets  of  lines  so  they  will  be 
exactly  over  each  other.  Now  locate  and  bore  holes 
for  two  pattern  pins,  boring  the  holes  through  both 
pieces.  Get  out  and  glue  together  two  or  more  pieces, 
from  which  to  turn  the  larger  cylinder,  being  sure  to 
make  them  long  enough  to  include  core-prints.  While 
the  glue  is  drying,  get  out  stock  and  turn  to  size  the 
smaller  cylinder,  remembering  that  core-prints  are 


FIG.  131. 


needed  on  this  also.  The  best  form  in  which  to  turn 
this  is  indicated  by  Fig.  131,  both  being  turned  from 
the  same  piece  of  wood.  These  may  now  be  nailed  in 
place  inside  the  circles  already  drawn  for  them  on  the 
double  web  piece.  Next  turn  the  larger  cylinder  to 
size,  including  the  core-prints.  There  are  two  ways 
this  may  be  fastened  to  the  web  part  of  the  pattern. 
One  is  to  saw  off  enough  from  two  sides  of  the  cylinder 
so  that  when  they  are  glued  to  the  web  they  will  equal 
the  diameter  of  the  cylinder.  These  may  now  be  glued 
on,  locating  them  by  the  center  lines  already  drawn  on 
the  web  pieces.  The  other  way,  which  is  in  some  re- 
spects the  better  way,  is  to  put  together  two  pieces  of 
wood  as  was  dDne  for  the  second  example,  Fig.  116,  and 
do  not  forget  the  core-prints,  but  turn  them  at  the  same 
time.  Cut  the  web  pieces  off  at  the  center  line  of  the 


PULLEY  PATTERNS  181 

cylinder,  and  cut  a  recess  in  each  half  of  the  cylinder, 
the  depth  of  recess  to  equal  the  thickness  of  one  of 
the  web  pieces,  measuring  from  the  flat  surface  of  the 
half  cylinder,  and  extending  to  the  center -of  the  cyl- 
inder. Do  not  cut  this  recess  into  the  core-prints. 
This  recess  must  be  cut  of  an  even  depth  so  that  the 
diameter  line  of  the  half  cylinder  and  one  side  of  the 
web  shall  be  in  the  same  plane  when  put  together. 
Of  course  both  halves  must  be  treated  in  the  same  way. 
This  makes  a  good  workmanlike  job,  leaving  no  end 
grain  at  that  end  of  the  pattern  as  would  be  the  case  if 
it  was  built  the  other  way.  After  fastening  the  cyl- 
inders in  place  the  cross  webs  may  be  made,  fitted  and 
fastened  in  place.  The  corners  of  the  web  pieces 
should  be  rounded  before  they  are  fastened  in  place, 
as  it  can  now  be  done  with  a  plane.  The  pattern  pins 
may  now  be  put  in,  the  two  halves  put  together  and 
finished  up.  The  small  fillets  required  may  be  put  in 
with  wax  after  the  first  coat  of  varnish  is  dry.  These 
fillets  should  extend  throughout  all  internal  angles, 
except  those  between  the  pattern  and  core-prints.  The 
two  core-boxes  may  now  be  made.  As  these  are  of  the 
same  general  shape  already  described,  it  will  not  be 
necessary  to  repeat  that  description  here. 

The  pattern  and  core-boxes  may  now  be  finished 
as  directed  on  page  225. 


CHAPTER  XV 
PATTERNS  FOR  CAST  GEARS 

The  next  class  of  work  to  be  taken  up  requires  the 
greatest  amount  of  care  and  attention  on  the  part  of 
the  pattern-maker,  as  in  order  to  obtain  the  best  results 
his  work  must  be  correct  in  all  its  details.  The  class 
of  work  referred  to  is  the  making  of  gear  patterns, 
especially  patterns  for  what  are  known  as  cast  gears. 
By  this  is  meant  gears  of  which  the  teeth  are  cast  to 
the  required  size  and  shape. 

There  are  two  general  ways  of  manufacturing  gears. 
One  way  is  to  cast  what  is  known  as  a  gear  blank, 
which  is  turned  to  size  and  the  teeth  cut  from  the  solid 
metal.  This  is  the  method  usually  employed  for  small 
work,  and  for  gears  that  are  required  to  run  very 
smoothly.  They  are  spoken  of  as  a  class  as  cut  gears. 
But  if  the  gears  are  large  and  of  coarse  pitch,  the  pat- 
terns are  made  with  the  teeth  of  the  approximate  size 
of  the  finished  teeth.  That  is,  each  surface  of  each 
tooth  on  the  pattern  is  treated  the  same  as  a  finished 
surface  on  any  pattern,  i.  e.,  about  one-eighth  inch  is 
allowed  for  finishing  or  machining.  After  the  casting 
is  made,  the  teeth  are  cut  on  the  gear  cutter  just  as  the 
full  blank  would  be  for  a  small  gear.  Casting  them  in 
this  way,  of  course,  saves  an  immense  amount  of  cut- 
ting, thereby  economizing  on  time  and  the  wear  of 
cutters. 

The  other  of  the  two  ways  of  manufacturing  gears 

182 


PATTERNS  FOR  CAST  GEARS 


183 


is  by  making  a  pattern  of  the  gear  with  teeth  complete, 
and  then  making  a  casting  from  that  pattern.  Gears 
made  in  this  way  are  called  cast  gears,  and  the  making 
of  patterns  for  this  purpose  will  now  be  explained : 

It  best  serves  the  purpose  of  this  volume  to  illus- 
trate some  general  principles  in  regard  to  making  gear 


FIG.  132. 


patterns  that  can  be  applied  by  the  student  to  any 
particular  case.  Consequently,  in  preference  to  a  gear 
of  any  specific  size,  patterns  .for  cast  gears  in  general 
will  be  considered.  The  part  to  be  considered  first 
is  the  rim  or  periphery  of  the  wheel,  to  which  the  teeth 
are  fastened.  There  are  several  ways  that  this  may  be 
built  up;  the  difference  is  mainly  in  regard  to  «the 


184  WOOD  PATTERN-MAKING 

method  of  holding  it  in  the  lathe  while  being  turned. 
The  actual  building  should  be  done  as  explained  for  the 
pulley  rim,  that  is,  with  segmental  pieces  of  wood 
of  the  required  size  and  thickness.  As  the  cross- 
section  is  of  somewhat  different  shape,  the  segments 
will  of  course  vary  also.  If  the  gear  is  to  be  large 
enough  so  that  both  sides  can  be  gotten  at  at  the  same 
time  while  running  in  the  lathe,  the  best  way  is  to 
build  up  the  rim  on  what  may  be  called  a  three-armed 
chuck.  This  is  made  as  illustrated  by  Fig.  132.  The 
width  of  the  arms  will  be  determined  by  the  size  of 
the  gear.  For  gears  up  to  two  feet  in  diameter,  pieces 
J/%  inch  thick  by  3  inches  wide  will  be  heavy  enough. 
The  length  of  the  arm  will  be  equal  to  the  radius  of  the 
rim  only.  These  arms  are  to  be  mitered  and  fastened 
to  a  disk  a  little  larger  than  the  face-plate  that  it  is 
proposed  to  use ;  the  fastening  is  to  be  done  with 
screws,  as  indicated,  Fig.  132.  The  face-plate  should 
be  put  on,  and  the  chuck  put  on  the  lathe ;  then  the  face 
of  the  arms,  for  a  distance  somewhat  more  than  the 
width  of  the  stock  for  the  rim,  should  be  faced  off  true. 

It  is  now  ready  to  have  the  segments  glued  on  for  the 
rim.  As  will  be  seen,  the  first  row  of  segments  must 
be  made  up  of  three  pieces  and  jointed  in  the  center  of 
each  arm.  After  this  is  glued  in  place,  the  rest  of  the 
structure  may  be  made  up  of  shorter  ones,  in  fact,  of 
any  length  desired.  The  building  process  should  be 
continued  in  this  way  until  completed,  leaving  the 
arms  of  the  chuck  as  near  the  center  of  the  rim  as 
possible. 

It  is  now  ready  to  be  turned  to  size  and  shape  as 
shown  in  Fig.  133,  which  should  be  done  with  scrap- 


PATTERNS  FOR  CAST  GEARS 


185 


ing  tools ;  it  should  be  tested  for  shape  with  a  templet. 
It  is  not  well  to  cut  the  arms  down  too  thin  until  the 
teeth  blocks  have  all  been  glued  on  and  turned  to  size. 
In  other  words,  all  the  turning  to  be  done  should  be 
completed  before  cutting  into  the  chuck  arms  very 
much  ;  otherwise  the  rim  may  spring.  When  all  the 
other  turning  is  done,  the  arms"  may  be  cut  almost 


.Section  on  A-B 


FIG.  133. 


through  with  very  little  clanger.  Of  course  the  more 
nearly  through  they  are  cut,  the  less  work  will  have 
to  be  done  by  hand  after  it  is  taken  from  the  lathe; 
this  should  be  left,  however,  until  the  tooth  blocks  are 
glued  on  and  the  turning  all  done. 

The  next  thing  to  do  is  to  mark  out  the  spaces  in 
which  to  fasten  the  tooth  blocks.  If  the  pitch  of  the 
gear  is  not  more  than  i  inch,  these  blocks  may  be  made 
of  such  a  size  that,  allowing  one  for  each  tooth,  they  will 


186 


WOOD  PATTERN-MAKING 


form  a  complete  circumference  around  the  rim.  The 
grain  of  the  blocks  must  be  perpendicular  to  the  side 
of  the  gear,  or,  in  other  words,  parallel  with  the  axis 
of  the  wheel.  They  should  be  made  of  good,  clear, 
straight-grained  wood,  thoroughly  seasoned.  Some 
kind  of  hardwood  such  as  mahogany  or  cherry  is  best 
at  least  for  standard  patterns. 


FIG.  134. 


There  are  several  ways  of  putting  these  blocks  on 
the  rim.  Three  ways  will  be  explained  that  will  include 
all  the  practical  ideas  and  principles  of  this  branch  of 
pattern-making.  In  all  three,  the  rim  at  its  present 
stage  will  be  laid  out  in  the  same  way,  that  is,  spaced 
into  as  many  spaces  as  it  is  required  to  have  teeth  in 
the  wheel.  The  three  ways  spoken  of  will  be  more 
clearly  understood  by  referring  to  Fig.  134. 

The  method  shown  by  the  tooth  A  is  what  may  be 
called  the  cheap  way.  In  this  case  the  teeth  are  formed 
before  being  fastened  in  place.  They  may  be  formed 


PATTERNS  FOR  CAST  GEARS 


187 


in  two  ways.  One  is  to  plane  up  strips  of  wood  to  the 
desired  shape,  and  then  cut  them  off  to  the  required 
length.  A  better  way  is  to  make  a  box  as  illustrated  by 
Fig.  135,  each  block  being  cut  to  exact  length  and 
held  in  place  by  a  screw,  as  shown.  Fig.  136  shows 
the  method  of  getting  the  shape  of  this  box.  In  using 


FIG.  135. 


this  box,  care  must  be  taken  not  to  cut  away  any  part 
of  it  in  planing  the  tooth  to  shape.  To  locate  a  tooth 
on  the  rim,  set  the  dividers  to  exactly  half  its  thick- 
ness ;  place  one  leg  on  the  center  marks  already  made, 
and  with  the  other  leg  make  a  mark  on  each  side ; 
these  marks  will  indicate  the  position  for  the  sides  of 
the  tooth.  Of  course  these  marks  must  be  squared 
across  the  face  of  the  rim  so  that  the  teeth  may  set 
square.  When  gluing  them  on  use  a  try-square  to 
test  them ;  do  not  depend  wholly  on  the  marks  for  this. 
The  above  method  does  very  well  .for  a  job  where  only 
one  or  two  wheels  are  wanted,  and  for  cases  where 
it  is  not  desired  to  go  to  the  expense  of  a  good  job  of 
pattern-making.  The  second  way  is  to  glue  all  the 
blocks  on  the  rim,  lay  them  out  in  that  position,  and 
then  cut  to  the  lines.  This  makes  a  good  job  when  prop- 


WOOD  PATTERN-MAKING 


erly  done,  but  it  is  rather  inconvenient  to  cut  the  teeth, 
especially  if  the  face  of  the  gear  is  very  wide.  There 
is  another  way  that  ia  known  as  the  dove-tailing 
method,  so  named  because  each  tooth  is  glued  to  a 
thin  block  let  in  to  the  rim.  One  disadvantage  of  this 
way  is,  that  if  the  dovetails  are  driven  a  little  too  tight, 
it  is  very  likely  that  the  rim  will  be  sprung,  and  the 
resulting  casting  will  not  be  round.  About  the  only 
advantage  claimed  for  this  method  is  that  one  or  more 
of  the  teeth  may  be  removed  and 
used  by  the  molder  for  patching  up 
a  broken  mold ;  but  this  can  be  at- 
tained in  another  way.  The 
method  of  dovetailing  is  illus- 
trated at  B,  Fig.  134.  It  is  a  very 
expensive  method,  and  is  now  al- 
most obsolete. 

The  best  way  to  fasten  and  form 
the  teeth  on  gear  patterns  is  the 
one  shown  in  the  center  of  Fig. 
134.  It  should  be  used  on  all 
standard  patterns.  This  method 
was  first  published  by  P.  G.  Dingey  in  the  "American 
Machinist."  Before  entering  into  the  details  of  this 
way,  some  of  its  advantages  should  be  noticed.  It 
does  away  entirely  with  the  objection  mentioned  in 
connection  with  the.  dovetailing  method,  viz.,  spring- 
ing the  rim  by  driving  the  dovetails ;  and  at  the  same 
time  it  permits  that  one  or  more  of  the  teeth  be  re- 
moved by  the  molder,  if  necessary.  Another  great 
advantage  gained  is  that  the  fillets  are  made  in  solid 
wood,  thus  producing  a  much  smoother  pattern  and 


FIG.  136. 


PATTERNS  FOR  CAST  GEARS  189 

casting.  None  of  the  other  methods  shown  have  this 
advantage.  In  the  dovetailing  method  a  very  thin  edge 
must  necessarily  be  left  at  this  point.  In  the  first  method 
described  a  wax  fillet  would  generally  be  used,  which 
in  the  course  of  frequent  use  is  very  liable  to  be  loos- 
ened by  the  shrinking  and  swelling  of  the  wood,  leav- 
ing the  pattern  rough  just  where  it  ought  to  be  the 
smoothest.  Another  advantage  in  the  method  under 
consideration  is  that  one-half  of  the  teeth  being  fas- 
tened on  with  screws,  each  alternate  tooth  may  be 
removed,  thus  making  room  for  working  those  glued  on. 
In  this  method  the  first  thing  to  be  done,  after  build- 
ing up  the  rim,  is  to  turn  the  rim  down  about  YZ  inch 
smaller  in  diameter  than  the  diameter  of  the  whole 
depth  circle,  or  to  the  point  lettered  D  in  Fig.  134. 
Then,  of  course,  the  tooth  blocks  will  have  to  be  made 
larger  by  that  amount  than  the  size  of  the  tooth  proper. 
After  the  rim  is  turned  to  size  it  should  be  spaced  as 
previously  suggested.  This  should  be  done  accurately 
so  that  each  tooth  may  come  in  the  center  of  each  block. 
One  set  of  lines  will  do  if  the  pitch  of  the  gear  is  not  too 
coarse  to  allow  the  stock  of  which  the  tooth  blocks  are 
to  be  made,  to  fill  the  spaces.  Otherwise,  two  sets  of 
lines  will  be  required,  and  pieces  must  be  glued  in 
between  the  blocks,  as  represented  at  E,  Fig.  134. 
When  the  blocks  are  ready  and  the  rim  is  marked  out, 
one  of  the  blocks  may  be  glued  in  place.  Do  not  get 
too  much  glue  on,  as  it  will  be  likely  to  make  trouble 
in  putting  on  the  next  block,  for  this  is  to  be  fastened 
on  without  any  glue.  With  a  brace,  and  a  bit,  of  the 
proper  size  for  the  screws  to  be  used,  bore  two  holes 
through  the  rim  as  near  the  center  of  the  space  for  the 

13 


190  WOOD  PATTERN-MAKING 

next  block  as  may  be ;  counter-sink  them  on  the  inside 
of  the  rim  to  receive  the  heads  of  the  screws.  Hold 
the  second  block  in  position,  and  with  a  brad  or  small 
drill  mark  on  the  block  the  places  for  the  screws,  and 
bore  them  with  a  suitable  sized  drill.  Now,  holding 
the  block  in  position  again,  insert  the  screws,  driving 
them  in  until  the  heads  are  slightly  below  the  surface 
of  the  rim.  This  process  should  be  carried  on  until 
the  blocks  are  all  fastened  on.  Be  very  careful  not  to 
glue  the  blocks  together  for  at  least  half  an  inch 
from  the  surface  of  the  rim,  and  also  not  to  glue  the 
blocks  having  screws,  to  the  rim,  or  it  will  make  trouble 
later  on.  In  getting  out  the  blocks  for  any  of  the  last 
three  methods  described,  they  should  be  made  about 
one-eighth  inch  longer  than  finished  size,  and  then 
turned  off  in  the  lathe  so  as  to  make  a  good  smooth 
surface  on  which  to  lay  out  the  pitch  circle,  base  circle 
and  tooth  curves,  and  also  on  which  the  spacing  of  the 
teeth  may  be  done.  When  the  blocks  have  been  glued 
on  and  allowed  to  dry,  the  whole  of  the  work  should  be 
put  in  the  lathe,  the  ends  of  the  tooth  blocks  turned  off 
even  with  the  edge  of  the  rim,  and  the  face  turned 
down  to  the  required  size.  After  this  is  done,  a  coat 
of  yellow  varnish  may  be  put  on  the  parts  that  are  to 
form  the  teeth.  This  makes  a  much  better  surface 
on  which  to  make  lines  than  does  the  bare  wood. 

There  are  several  ways  of  laying  out  the  tooth 
curves  on  the  pattern.  First,  however,  it  must  be  de- 
cided what  method  is  to  be  used  for  developing  these 
tooth  curves.  These  may  be  developed  by  the  epi- 
cycloidal  curve,  by  the  odontograph,  or  by  the  involute 
curve.  It  is  not  intended  in  this  volume  to  enter  into 


PATTERNS  FOR  CAST  GEARS  191 

a  discussion  of  the  merits  or  demerits  of  any  one  of 
these  systems,  or  even  to  explain  them,  but  simply 
to  call  attention  to  them  and  to  indicate  one  or  two 
ways  of  applying  them  to  the  pattern.  Theoretically, 
the  use  of  the  odontograph  is  probably  the  best,  espe- 
cially for  large  work ;  but  for  comparatively  small  work 
a  careful  use  of  the  dividers  will  give  as  good  results, 
and  if  only  single  curve,  or  involutes,  are  desired,  the 
use  of  the  dividers  afford  the  quickest  way.  In  decid- 
ing what  method  of  development  is  to  be  used,  one  or 
two  further  facts  should  be  considered.  The  involute 
form  will  give  uniform  angular  velocity  if  the  distance 
between  the  centers  of  any  two  gears  does  not  remain 
uniform,  as,  for  instance,  in  the  feed  rolls  of  the  com- 
mon rotary  knife  planer.  Other  forms  of  teeth  will 
not  do  this.  Again,  if  dividers  are  used  for  marking 
out  these  forms  on  the  pattern,  the  single  curve  is 
much  more  quickly  laid  out.  The  single  curve  method 
is  fully  illustrated  by  Fig.  137,  and  is  what  may  be 
called  a  simple  shop  method.  It  can  be  used  to  advan- 
tage when  the  data  supplied  by  the  draftsman  to  the 
pattern-maker  does  not  indicate  any  particular  method. 

The  first  thing  that  needs  to  be  known  is  the  pitch 
and  number  of  teeth.  Of  course  this  was  learned  be- 
fore building  up  the  pattern  ;  so  all  that  needs  now  to  be 
done  is  to  apply  this  knowledge  to  the  work. 

In  order  that  the  student  may  apply  this  knowledge 
intelligently  it  will  be  well  for  him  to  make  a  copy  of 
Fig-  I37>  using  data  obtained  by  computing  the  differ- 
ent dimensions  for  some  specified  gear ;  for  instance,  a 
gear  that  must  have  45  teeth,  il/2  inches  circular  pitch, 
single  curve  involute  tooth  curves.  To  find  the  diameter 


192  WOOD  PATTERN-MAKING 

of  the  gear,  which  is  the  first  thing  to  do,  multiply  the 
number  of  teeth  by  the  circular  pitch — 45x1^  inches^ 
67.5  inches  -^  3.1416  =  21^/2  inches,=  diameter  of  tr-e 
gear.  Then  the  radius  of  the  gear  and  also  of  the  pitch 
circle  will  be  iofy  inches.  With  this  as  radius,  draw 
arc,  A.  Now  set  the  dividers  to  1^/2  inches  (the  cir- 
cular pitch),  and  space  off  four  or  five  spaces  along  the 
arc  A  for  the  centers  of  the  teeth.  Next  space  off  the 
thickness  of  the  teeth,  a,  which,  according  to  the  data 
given  in  connection  with  Fig.  137,  is  7/15  of  the  pitch 
— 7/15  of  i*/t  inches  =  \\  inch;  set  the  dividers  to 
one-half  of  this  and  set  off  on  each  side  of  the  center 
points  already  located.  This  will  leave  8/15  of  an 
inch,  or  approximately  \\  inch  for  spaces  between  the 
teeth.  Compute  the  distance,  c,  the  face  of  the  tooth, 
which  must  be  5/15  of  the  pitch,  or  approximately  fy 
inch ;  measure  that  distance  outside  of  arc  A,  and 
describe  another  arc  B,  thus  forming  the  addendum 
circle.  Now  draw  arc  F  with  radius  equal  to  %  of 
the  pitch  diameter,  viz.,  5^  inches.  Next  set  dividers 
to  a  distance  equal  to  y±  of  the  pitch  radius;  set  one 
leg  of  the  dividers  in  one  of  the  points  representing 
the  sides  of  the  teeth  and  draw  arc  G.  The  point  where 
arcs  F  and  G  intersect  is  the  point  through  which  to 
draw  the  base  circle  C ;  draw  base  circle  through  this 
point.  Now  set  dividers  to  radius  of  arc  G,  and,  with 
one  leg  on  this  base  circle  as  center,  draw  the  tooth 
curves  through  the  points  already  located.  The  mak- 
ing of  this  drawing  on  paper  will  furnish  all  that  is 
necessary  for  laying  out  the  teeth  en  the  pattern,  which 
may  now  be  done. 


PATTERNS  FOR  CAST  GEARS 


193 


The  first  line  to  put  on  the  work  will  be  the  pitch 
circle ;  divide  this  into  as  many  equal  parts  as  there 
are  to  be  teeth  in  the  gear;  this  is  for  the  purpose  of 
locating  the  center  of  each  tooth.  In  doing  this  it  will 
l)e  found  advantageous  to  commence  at  one  side  of 


A=Pitcn  Circle. 
B-Addenduro  Circle 
C-B<xse  Circle 
D;Wfool»  De|>Tb  Circle 
El-Working  Def)th  Circle 
F-Rod.os-^:  Pitch  Circle 
G-Rodi  us  =  ^- "Pitch 
U-CenTer  oi  Ge^r 

o-'Ts  ef  "Ktth 
U.{|  .f  P.tcb 
c-S  «t  Ti'tth. 

d,.^    of   Pitch 

<3    6«      -  o 


the  center  of  tooth  block  for  the  trial  spacing;  then 
having  the  dividers  set  to  the  correct  distance,  start 
from  the  center  of  a  block.  Then  there  will  not  be 
several  points  to  confuse  one  in  fixing  the  correct  one 
for  the  center  of  the  tooth,  as  is  likely  to  be  the  case 


194  WOOD  PATTERN-MAKING 

if  the  centers  of  the  blocks  are  used  for  the  trial  divi- 
sion. Now  set  the  dividers  to  one-half  of  the  tooth 
thickness  as  derived  from  Fig.  137  at  a,  and  mark  a 
point  on  each  side  of  the  tooth  centers ;  this  will  locate 
the  sides  of  the  teeth.  The  base  circle  C,  Fig.  137, 
should  now  be  put  on  ;  its  diameter  is  found  as  indicated 
by  arcs  F  and  G.  Now  setting  the  dividers  to  one- 
fourth  of  the  radius  gear,  as  at  G,  Fig.  137;  proceed 
to  describe  tooth  curves,  being  very  careful  that  the 
arc  runs  through  the  points  located  for  the  side  of  the 
tooth  on  the  pitch  circle.  The  centers  for  these  tooth 
curves  are  all  on  the  base  circle.  At  the  points  where 
these  tooth  curves  intersect  the  addendum  circle,  15, 
Fig.  137,  lines  must  be  drawn  square  across  the  face 
of  the  pattern,  and  the  opposite  side  laid  out  with  cor- 
responding curves,  each  curve  starting  from  the  point 
where  these  squared  lines  intersect  the  corner.  Arcs 
with  radius  of  1/6  of  f  for  fillets  at  the  base  of  all  the 
teeth  will  now  be  put  in,  which  will  complete  the  laying 
out  of  the  teeth. 

The  next  work  to  be  done  is  to  saw  out  on  a  band- 
saw,  if  one  is  available,  the  wood  between  the  teeth  to 
form  the  spaces.  This  should  be  done  very  carefully  ; 
leave  one-half  of  the  marks  on  the  work  so  that  there 
will  remain  very  little  to  be  done  with  chisel  and  gouge. 
The  fillets  will  have  to  be  made  with  small  gouge,  as 
the  ordinary  band-saw  is  too  wide  to  turn  in  so  small  a 
curve  as  is  required  in  small  or  medium  sized  work.  If 
a  gear  of  coarse  pitch  was  being  made,  there  would  be 
little  difficulty  in  making  the  saw  do  most  of  that  work 
also.  If  the  teeth  were  put  on  the  rim  as  suggested 
for  standard  work — that  is,  each  alternate  tooth  glued 


PATTERNS  FOR  CAST  GEARS  195 

on,  and  the  others  fastened  with  screws — then  by 
taking  out  those  with  screws,  the  finishing  can  be 
done  very  easily ;  the  teeth  so  taken  out  should  be 
numbered  and  corresponding  numbers  put  on  the 
spaces,  so  that  they  may  be  put  back  in  their  propes 
places  after  being  finished.  The  temporary  arms  of 
the  chuck  may  now  be  cut  through,  thus  finishing  up 
the  work  of  making  the  rim  and  teeth.  The  shape  of 
this  rim  may  be  more  clearly  seen  by  referring  to  Fig. 
133.  The  way  of  attaching  the  arms  also  is  shown  in 
this  figure,  as  well  as  in  Fig.  134. 

The  next  process  is  to  make  the  spider,  or  arms. 
This  may  be  done  as  described  in  the  making  of  the 
8-inch  pulley  pattern,  except  that  in  this  case  they 
must  be  made  of  one  thickness  and  fastened  in  as 
shown  in  Figs.  133  and  134. 

As  these  arms  are  made  of  one  thickness,  one  side 
will  be  turned  up  after  the  face-plate  is  removed.  This 
may  be  done  in  a  cup-chuck  shown  by  Fig.  56,  in  the 
chapter  on  Turning.  In  this  case  the  cup  will  be 
turned  out  to  fit  the  hub  already  turned.  The  arms  will 
be  made  of  the  same  elliptical  shape  and  in  the  same 
way  as  described  in  the  case  of  the  8-inch  pulley,  Fig. 
124. 


BEVEL  GEAR  PATTERNS. 

Before  taking  up  the  construction  of  bevel  gear  pat- 
terns, it  will  be  well  to  say  something  about  the  lines 
required  for  laying  them  out.  The  first  thing  is  to 
make  two  lines  at  right  angles  to  each  other,  to  repre- 


sent the  center  line  of  the  shafts  on  which  the  bevel 
gears  are  to  be  fastened.  Bevel  gears  may  be  made 
to  run  shafts  at  other  angles  than  right  angles ;  if  this  is 
required,  the  first  two  lines  laid  down  must  be  drawn 
to  this  angle.  The  next  step  is  to  determine  the  size 
and  the  ratio  of  the  pair  of  bevel  gears  to  be  made. 

196 


PATTERNS  FOR  CAST  GEARS 


197 


The  pitch  diameter  of  a  bevel  gear  is  always  measured 
at  the  large  end.  The  pitch  of  the  teeth  is  also  meas- 
ured and  calculated  for  this  end.  Having  determined 
on  the  size  of  the  gear,  set  the  dividers  to  the  pitch 
radius  of  the  gear  and  prick  off  this,  equidistant  from 
line  A  B,  in  Fig.  138,  which  will  give  the  pitch  diame- 
ter. Now  proceed  by  laying  down  the  other  lines  as 


FIG.  139. 

in  Fig.  138.  Notice  that  the  teeth  are  not  developed 
on  the  pitch  circle,  but  on  a  projected  circle,  the  center 
of  which  is  obtained  by  producing  the  line  that  forms 
the  end  of  the  teeth  back  until  it  intersects  the  center 
line  of  the  gear  at  H ;  the  small  end  is  treated  in  the 
same  way,  which  locates  the  center  for  that  end  at  I. 
The  dimensions  of  tooth  elements  may  be  obtained 
from  Fig.  137.  The  drawing  makes  it  clear  as  to  how 
a  bevel  gear  should  be  laid  out. 

The  building  of  the  pattern  may  now  be  considered. 
The  first  thing  to  do  is  to  select  a  chuck  of  proper  size, 
if  we  have  one,  or  make  one  if  we  have  not.  A  chuck 


198 


WOOD  PATTERN-MAKING 


for  this  purpose  may  be  built  as  shown  by  Figs.  139 
or  140,  if  very  large.  The  rim  at  A  may  be  left  off  if 
thought  best;  but  its  presence  is  an  advantage  if  it 
becomes  necessary  to  use  handscrews  for  holding  the 
material  on  the  chuck  during  the  process  of  gluing, 
for  the  handscrews  may  all  be  set  to  the  same  size, 
and  so  more  quickly  applied.  This  is  quite  an  advan- 


FIG.  140. 


tage,  because  the  glue  drys  very  quickly.  The  chuck 
will  need  to  be  faced  off  to  a  true  surface,  and  some 
fairly  thick  paper  glued  on  the  part  where  the  seg- 
ments for  the  rim  are  to  be  fastened  on.  With  this 
exception,  the  process  of  building  this  rim  will  be  the 
same  as  for  the  8-inch  pulley.  The  laying  out  and  the 
sawing  of  the  cants  will  also  be  the  same,  except  that 
each  layer  will  have  to  be  described  with  different 
radii.  The  necessity  for  this  will  be  readily  seen  by 
consulting  Fig.  141,  which  shows  the  rim  as  it  will 
appear  after  being  built  on  to  the  chuck,  and  before  it 
is  turned.  When  there  have  been  enough  segments 


PATTERNS  FOR  CAST  GEARS 


199 


built  on,  and  the  glue  has  dried,  it  is  ready  to  be  turned 
to  shape,  as  shown  by  Fig.  141  ;  in  turning  it,  get 
around  into  the  work  at  point  P  as  far  as  possible. 

It  is  now  ready  to  be  taken  off  the  chuck,  which  can 
very  readily  be  done  by  introducing  a  chisel  between 


FIG.  141.  FIG.  142. 


the  work  and  the  chuck,  and  driving  it  lightly  at  several 
places  around  the  circumference.  This  will  cause  the 
paper  that  is  glued  between  the  work  and  chuck  to 
split,  allowing  the  work  to  come  off,  without  any  dam- 
age to  either.  The  rim  must  now  be  mounted  on  the 
chuck,  with  the  opposite  side  out.  The  best  way  to 
locate  it  on  the  chuck  so  that  it  will  be  concentric  with 
the  lathe  spindle  (as  it  must  be  in  order  that  the  inside 
and  outside  may  be  concentric)  is  to  turn  a  small  V- 


200 


WOOD  PATTERN-MAKING 


shaped  groove  into  the  chuck  that  will  exactly  fit  the 
corner  of  the  rim  at  the  point  marked  R,  Fig.  142.  The 
work  must  be  fastened  to  the  chuck  this  time  with 
screws  put  through  the  chuck.  To  do  this,  bore  holes 
through  the  chuck,  at  the  bottom  of  the  V-groove  just 
made,  of  a  suitable  size  for  the  screws  selected.  The 
number  of  screws  to  be  used  will,  of  course,  be  deter- 


FIG.  143. 


FIG.  144. 


mined  by  the  size  of  the  work :  from  four  to  six  will  be 
enough  for  work  up  to  three  feet  in  diameter.  Now 
take  the  chuck  off  the  lathe,  and,  having  laid  the  rim 
on  the  bench  with  its  proper  side  up,  lay  the  chuck 
on  it  and  drive  the  screws  through  the  chuck  into  the 
rim.  It  is  now  ready  for  the  lathe  again,  and  may  be 
turned  to  the  size  and  shape  indicated  at  S  and  S,  Fig. 
142.  Turn  it  small  enough  so  that  the  tooth  blocks 
may  be  put  on  as  indicated  at  K,  Fig.  143,  and  more 
plainly  shown  in  Fig.  134  at  C  C.  The  arms  may  now 
be  made,  and  mitered  together  in  the  center,  with  a 
piece  on  each  side  for  strength ;  the  same  pieces  also 
serve  as  fillets,  as  indicated  at  B,  Fig.  144.  The  arms 


PATTERNS  FOR  CAST  GEARS 


201 


should  be  set  into  the  rims  as  shown  at  D,  .Fig.  144, 
before  the  work  is  taken  from  the  chuck.  The  vertical 
arms  C  C,  with  the  central  hub  E,  must  be  left  loose 
so  they  will  lift  with  the  cope.  These  will  be  built 
together  as  shown  by  Fig.  145. 


FIG.  145. 


CHAPTER   XVI 
PIPE  FITTINGS 

Another  large  and  interesting  class  of  patterns  are 
those  required  in  the  manufacture  of  cast-iron  pipe 
fittings,  two  types  of  which  will  now  be  taken  up.  The 
castings  are  what  is  known  as  a  bend,  shown  at  Fig. 
146,  and  an  elbow,  shown  at  Fig.  153.  The  larger  part 


FIG.  146. 


of  the  pattern  work  can  be  done  on  the  lathe  for  both 
of  these  examples. 

The  pipe  bend  will  be  taken  up  first.  The  first  thing 
to  do  is  to  prepare  a  chuck  large  enough  in  diameter, 
turn  its  face  perfectly  flat,  and  glue  paper  all  over  it. 

The  stock  required,  as  illustrated  by  Fig.  147,  must 
be  large  enough  to  contain  the  size  of  pattern  it  is  pro- 
posed to  build,  indicated  by  the  circle  on  the  figure. 

202 


PIPE  FITTINGS 


203 


This  should  be  put  on  the  chuck  in  two  pieces,  as 
shown  in  the  cut ;  each  half  has  one  side  and  one  edge 
planed  straight  and  at  right  angles  to  each  other,  as 


FIG.  147. 


FIG.  148. 


the  edges  are  to  form  the  joint.  These  must  be  so 
placed  on  the  lathe  that  the  joint  shall  be  exactly  on 
the  center  of  the  lathe.  The  best  way  to  do  this  has 
already  been  explained  in  connection  with  core-box 
ends,  page  1.46.  They  are  now  to  be  turned  to  the  shape 


204 


WOOD  PATTERN-MAKING 


indicated  by  Fig.  148.  The  next  parts  to  be  made  are 
those  shown  at  Fig.  149.  These  must  be  made  in 
halves  and  turned.  Before  they  are  turned,  a  pattern 
pin  should  be  put  into  each,  so  that  it  will  not  have 
to  be  done  after  the  pattern  is  completed.  It  is  always 


FIG.  149. 


Ho.  150. 


best  to  put  in  these  pins  before  the  turning  is  done. 
After  the  pieces  are  turned,  the  parts  should  be  fitted 
together  as  shown  at  Fig.  150.  The  part  marked  a 
should  be  made  square,  as  shown  at  e,  Fig.  149.  Of 
course,  both  halves  are  to  be  made  in  the  same  way. 
The  core-box  for  this  pattern  is  shown  at  Fig.  151. 
The  circular  part  d  can  be  made  on  the  lathe ;  the  way 
is  clearly  shown  in  Fig.  152.  The  grooves  marked  b 
may  be  made  in  one  piece  of  lumber,  and  made,  of 


PIPE  FITTINGS 


205 


course,  with  the  core-box  plane.  If  it  is  desired  to 
make  this  very  strong,  a  piece  of  board  is  nailed  on 
the  bottom,  as  indicated  at  c. 


FIG.  151. 


FIG.  152. 


As  elbows  are  usually  cast  in  pairs  to  save  work  in 
the  foundry,  the  pattern  must  be  made  double.  The 
economy  resulting  is  great,  as  it  will  take  but  very 


206 


WOOD  PATTERN-MAKING 


little  more  of  the  molder's  time  to  make  the  mold  for 
both  than  for  one.  Besides  the  core  can  be  more  easily 
set  and  held  in  place  if  two  are  made  in  the  one  mold. 
If  only  one  is  made,  a  chaplet  would  be  needed  to  hold 
the  core ;  or  else  very  long  prints  would  have  to  be  put 
on  the  pattern,  either  of  which  would  increase  the  work 
of  the  molder. 


FIG.  154. 


The  pattern  for  the  elbow  is  a  little  more  complicated 
than  for  the  bend,  though  the  work  is  quite  similar  in 
character.  It  is  made  as  follows:  A  ring,  as  shown 
at  Fig.  154,  is  first  turned,  with  its  cross-section  as 
indicated  at  a.  The  best  way  to  make  this  is  to  get 
out  four  pieces  with  the  grain  as  indicated  in  the  figure  ; 
that  is,  the  chord  of  the  curve  should  be  parallel  with 
the  grain  of  the  wood.  Fit  them  together  very  accu- 
rately, and  glue  them  to  a  chuck  (but  not  to  each 
other)  that  has  been  previously  covered  with  paper, 
and  turn  them  to  the  required  shape.  A  solid  piece 


PIPE  FITTINGS 


207 


may  be  used  and  cut  into  the  required  number  of  pieces 
after  being  turned,  but  this  method  is  not  as  good. 
In  mounting  these  pieces  on  the  chuck,  care  should  be 


FIG.  155. 

taken  to  see  that  the  point  where  they  meet  is  exactly 
on  the  center  of  the  lathe.  Now  two  pieces  are  re- 
quired like  Fig.  155.  These  will  be  made  in  halves  and 


FIG.  156. 


turned.  Both  will  be  alike,  except  that  on  one  the 
shape  af  A  will  be  left  the  full  size  and  of  a  length 
to  equal  A  in  Fig.  156.  The  one  made  like  Fig.  155 
will  be  cut  in  two,  the  parts  B  and  C  squared  as  at  E, 


208 


WOOD  PATTERN-MAKING 


Fig.  149.     They  are  then  fitted  into  the  first  piece  as 
shown  at  B  and  C,  Fig.  156. 

The  core-box  to  go  with  this  pattern  is  shown  at 


FIG.  157. 


Fig.  157.  The  circular  parts  A  and*B  can,  of  course,  be 
made  on  the  lathe  in  the  same  way  as  for  the  core-box 
shown  at  Fig.  151. 


CHAPTER  XVII 
ESTIMATING  WEIGHT  OF  CASTINGS 

As  the  pattern-maker  is  frequently  required  to  esti- 
mate the  weight  of  a  casting  from  the  pattern,  and 
sometimes  even  from  the  drawing,  with  more  or  less 
accuracy,  we  will  here  point  out  some  of  the  methods 
employed  in  arriving  at  such  an  estimate.  The  degree 
of  accuracy  demanded  is  generally  determined  by  the 
value  of  the  metal  or  by  the  purpose  of  the  required 
casting.  In  the  case  of  large  castings  it  may  be  suffi- 
cient to  arrive  at  the  weight  within  two  or  three  hun- 
dred pounds,  but  for  small  castings  it  may  be  neces- 
sary to  come  within  one  pound  or  even  a  few  ounces. 
One  way  in  which  this  may  be  done  is  to  calculate  the 
number  of  cubic  feet  in  a  large  casting  or  cubic  inches 
in  a  small  one,  and  then  convert  this  number  into 
pounds  by  multiplying  it  by  a  given  constant.  The 
constant  will  of  course  be  different  for  each  kind  of 
metal.  A  list  of  constants  for  this  purpose  for  metals 
in  common  use  may  be  found  at  the  end  of  this  chapter. 

When  the  weight  of  a  given  casting  is  required,  the 
following  rule  is  applied :  First,  find  by  measurement 
and  calculation  the  cubical  contents  of  the  pattern  in 
feet  or  inches ;  multiply  this  by  the  given  constant 
for  the  metal  to  be  used ;  the  quotient  is  the  number 
of  pounds  the  casting  may  be  expected  to  weigh.  We 
use  the  word  "expected"  advisedly,  as  there  are  so 
many  contingencies  that  may  arise  in  the  making  of 
the  casting  over  which  the  pattern-maker  has  no  con- 

209 


210  WOOD  PATTERN-MAKING 

trol  that  the  estimate  made  can  be  only  an  approxi- 
mate one.  One  of  these  contingencies  is  the  rapping 
of  the  pattern  which  may  make  an  appreciable  differ- 
ence in  the  weight  of  small  castings.  Another  is  the 
different  densities  of  the  metal  in  the  same  mold,  which 
will  cause  variations  that  cannot  be  computed.  Again, 
a  mold  that  is  unevenly  rammed — harder  and  softer  in 
different  parts — will  make  a  casting  that  will  vary  in 
weight.  The  softer  parts  of  the  mold  will  allow  the 
casting  to  swell,  and  so,  being  larger  than  the  pattern, 
will  be  heavier  than  calculated.  These  and  many  other 
things  will  interfere  to  make  the  weight  of  a  casting 
vary  from  its  calculated  weight. 

The  most  accurate  way  to  obtain  the  weight  of  a 
casting  from  the  pattern  is  by  what  is  known  as  specific 
gravity.  The  pattern  is  steadily  immersed  in  water 
in  a  tank,  the  displaced  water  is  allowed  to  overflow 
into  another  vessel  and  is  then  weighed.  Thus,  sup- 
pose a  pattern  displaced  3^4  pounds  of  water;  if  this 
is  multiplied  by  the  specific  gravity  of  iron  (7.3),  the 
resulting  quotient  will  give  the  weight  of  the  casting 
in  pounds.  Because  of  the  many  difficulties  to  be  over- 
come, such  as  suitable  apparatus,  the  injury  to  wood 
patterns,  the  presence  of  core-prints,  etc.,  this  method 
is  not  employed  except  where  accurate  weight  is  of 
great  importance. 

Another  way  is  to  weigh  the  pattern  and  multiply 
that  weight  by  16,  the  generally  accepted  ratio  between 
pine  wood  and  cast-iron.  This  leaves  out  of  consider- 
ation the  various  densities  of  different  specimens  of 
wood,  the  presence  of  nails  or  screws  or  other  foreign 
substances  in  the  pattern,  and  core-prints,  if  any. 


ESTIMATED  WEIGHT  OF  CASTINGS 


211 


The  best  practical  way  is  the  method  first  mentioned, 
viz.,  ascertaining  the  cubical  contents  of  the  pattern 
and  multiplying  it  by  a  known  constant.  This  method 
may  be  used  before  the  pattern  is  built,  as  the  drawing 


,  _  _  8-  3— 

FIG.  158. 


_L 


will  give  all  the  necessary  data.  The  accuracy  attained 
by  this  method  wijl  depend  largely  on  the  correctness 
with  which  the  measurements  and  computations  are 
made.  To  illustrate  this  method  we  will  use  just  one 
example,  a  drawing  of  which  is  found  in  Fig.  158, 
which  represents  the  bottom  plate  for  a  cupola  furnace. 


212  WOOD  PATTERN-MAKING 

In  this  example  the  length,  width  and  thickness  may 
be  multiplied  together  to  obtain  its  cubical  contents. 
These  sizes  are  9  feet  6l/2  inches  x  8  feet  9  inches  x  2 
inches  =  24045  cubic  inches ;  add  to  this  659.73  cubic 
inches  for  the  ring  A,  and  also  192  cubic  inches  for 
four  door-hinge  lugs  B,  giving  as  the  total  24896.73 
cubic  inches.  From  this  number  must  be  subtracted 
the  cubical  contents  of  the  circular  opening  C,  which 
is  8143.02  cubic  inches,  thus  leaving  16753.71  cubic 
inches  to  be  multiplied  by  the  constant  .263  for  cast- 
iron,  so  that  this  casting,  if  made  of  iron,  will  weigh 
approximately  4406.22  pounds.  This  will  be  very  nearly 
correct  if  the  mold  is  rammed  so  that  the  casting  is  like 
the  pattern,  that  is,  without  any  swollen  places. 

For  a  rough  approximation,  weighing  the  pattern 
and  multiplying  its  weight  in  pounds  by  16  is  of  course 
the  easiest  and  quickest  way  and  is  the  one  most  used 
by  foundry  men  in  estimating  the  amount  of  iron  to  be 
melted  for  a  heat  or  a  certain  casting. 

The  following  constants  may  be  used  as  multipliers 
for  the  metals  named  when  cast : 

TABLE  OF  CONSTANTS. 

WEIGHT  PER  WEIGHT  PER 

METAL.  CUBIC  INCH.  CUBIC  FOOT. 

IRON 263  Ibs.  451  Ibs. 

STEEL 288  Ibs.  499  Ibs. 

BRASS 3      Ibs.  524  Ibs. 

LEAD 41    Ibs.  708  Ibs. 

COPPER 32    Ibs.  537  Ibs. 

TIN..                                                                    .   .266  Ibs.  451  Ibs. 


CHAPTER  XVIII 
MISCELLANEOUS  PATTERN  WORK 

Fig.  160  shows  a  good  method  of  building  patterns 
that  are  flat,  square,  or  rectangular,  and  of  compara- 
tively thin  in  cross  section.  The  casting  required  is 
shown  by  Fig.  159.  It  is  a  common  form  of  steam  chest 


FIG.  159. 

cover.  In  building  the  pattern,  the  central  part  is  made 
up  of  narrow  strips  set  into  a  grove  in  the  outside 
pieces.  These  are  mitered  together  and  tongues  driven 
into  grooves  as  shown  by  dotted  lines  at  A,  Fig.  160. 
The  diagonal  ribs  are  made  and  halved  together  and 
then  cut  to  the  shape  shown.  They  should  be  left  loose 
and  pinned  in  place  with  pattern  pins,  so  that  the 

213 


214 


WOOD  PATTERN-MAKING 


molder  may  take  them  off  in  order  to  lay  the  pattern 
flat  on  the  molding  board  during  the  first  operation 
in  molding.  This  is  necessary,  as  in  order  to  have 
the  side  C  good  and  sound,  it  must  be  cast  with  that 
side  down  ;  then  the  ribs  will  come  in  the  cope. 


FIG.  160. 


SKELETON  PATTERNS 

The  term  "skeleton  patterns"  embraces  a  large 
variety  of  patterns ;  it  refers  to  those  that  are  made  of 
a  combination  of  wood  and  sand ;  that  is,  both  wood 
and  sand  are  used  to  form  the  complete  pattern.  The 
pattern-maker  constructs  the  required  woodwork,  and 


Q G (Or 


FIG.  161. 


the'molder  makes  the  rest  of  the  pattern  with  sand. 
The  sand  commonly  used  for  this  class  of  work  is  called 
loam. 

One  example  of  this  class  of  patterns  is  shown  by 
Fig.  161.  It  is  a  skeleton  pattern  of  a  pipe  bend,  from 
which  only  one  or  two  castings  are  wanted.  The 
drawings  give  a  good  idea  of  the  general  make-up  of 
the  pattern.  The  core  and  method  of  making  it  are 

215 


216 


WOOD  PATTERN-MAKING 


shown  at  Fig.  162.  The  parts  the  pattern-maker  would 
have  to  make  in  order  that  the  core-maker  could  pro- 
duce this  core,  are  the  core-board,  as  it  is  called,  indi- 
cated by  b  and  the  strickle  shown  at  c  in  Fig.  162.  The 
core-board  is  simply  a  piece  of  board  planed  up  true 
on  both  sides,  and  cut  to  the  correct  shape.  Its  side 
d  is  cut  in  such  a  way  that  when  the  strickle  is  set  at 


FIG.  162. 


right  angles  to  it  and  slid  along  its  length,  it  will  give 
the  desired  size  and  shape  to  the  core.  When  the 
molder  uses  this  apparatus,  he  first  lays  this  prepared 
core-board  on  an  iron  plate,  and  clamps  or  fastens  it 
down  so  it  cannot  move.  He  piles  on  some  sand  and 
then  slides  the  strickle  along  so  that  the  point  E 
remains  in  contact  with  edge  d,  taking  care  to  keep 
it  perpendicular  to  the  straight  part,  and  to  keep  the 
cutting  edge  exactly  radial  in  passing  along  the  curved 
part.  If  there  is  any  point  on  the  sand  that  the  strickle 
does  not  touch,  more  sand  is  put  on  and  the  strickle 
again  passed  over  it.  This  process  is  continued  until 
a  good  smooth  surface  is  produced.  The  core-board 


MISCELLANEOUS  PATTERN  WORK  217 

is  now  removed,  and  the  plate  with  the  complete  half 
core  on  it  set  into  the  core  oven  to  be  baked.  To  make 
the  other  half,  the  core-board  is  turned  over  and  the 
process  repeated.  These  two  halves  are  baked,  and, 
when  hard,  are  pasted  together,  so  forming  the  com- 
plete core. 

The  making  of  the  pattern  is  carried  out  in  a  very 
similar  way,  but  requires  more  work  on  the  part  of  the 
pattern-maker.  The  first  thing  is  to  prepare  two  boards 
of  suitable  thickness  for  the  job ;  this  is  determined 
by  the  size  of  the  pattern  to  be  made.  One  of  these 
boards  is  shown  at  a  Fig.  161.  They  will  be  sawn  out 
to  the  shape  of  the  pipe  on  its  axial  line,  including  the 
core  prints. 

These  boards  are  pinned  together  the  same  as 
would  be  done  if  a  complete  wooden  pattern  was  to 
be  made.  The  flanges  f  f  are  also  to  be  cut  out  so  that 
they  will  fit  over  the  board  at  the  correct  points.  The 
semi-circular  pieces  d  d  are  also  cut  out  and  fastened 
on  at  equal  distances,  and  also  for  the  core  prints  c  c. 
Two  strickles  will  be  needed,  similar  to  the  one  used 
for  making  the  core,  Fig.  162  c,  one  for  the  body  of 
the  pattern,  and  one  for  the  prints.  The  moulder 
completes  the  pattern  by  laying  down  one  of  these 
boards  on  the  bench,  with  the  pieces  all  fastened  in 
place,  puts  on  sand,  filling  up  the  spaces,  and  then 
passes  the  strickle  over  it,  thus  making  a  smooth  sur- 
face the  same  as  for  the  core.  The  other  half  is  made 
the  same  way.  When  the  pattern  is  complete  the 
molder  scatters  parting  sand  all  over  it  so  it  will  leave 
the  mold  freely. 

Another    class   of    skeleton    patterns    is    illustrated 


218 


WOOD  PATTERN-MAKING 


by  Fig.  163.  It  represents  a  pattern  for  a  curved  cast- 
iron  plate,  over  which  a  blacksmith  or  boiler-maker  may 
bend  or  form  a  plate  of  wrought  iron  or  steel.  Instead  of 
making  a  complete  pattern,  which  would  be  a  slow  and 
expensive  process,  a  frame  is  made  as  shown,  and 
halved  together  at  the  corners.  The  rest  of  the  pattern 


FIG.  163 

will  be  made  by  the  molder,  with  the  strickle,  shown 
at  A  in  the  figure.  Flat  plates  of  large  area  may  be 
made  in  this  way,  that  is,  with  the  open  frame  and 
strickles,  thereby  saving  lumber  and  also  a  large 
amount  of  pattern  work.  A  pattern  of  this  kind  may 
be  molded  by  first  bedding  the  frame  in  the  nowel, 
or  if  too  large  for  that,  in  the  floor.  Then  fill  the  inside 
with  sand,  and  strike  it  off  even  with  the  top ;  put  on 
parting  sand  and  then  ram  up  the  cope.  Lift  off  and 
set  to  one  side.  With  a  strickle  cut  like  A,  Fig.  163, 
with  shoulder  B  the  same  depth  as  the  thickness  of 
the  plate,  cut  out  the  sand  to  that  depth.  Now  take  out 
the  frame  or  pattern,  and  there  is  left  a  cavity  in  the 
sand  of  the  size  and  thickness  of  the  required  casting. 


GLUING  FEATHER-EDGED  BOARD 

In  building  some  large  patterns  it  becomes  neces- 
sary to  glue  on  what  may  be  called  a  feather-edged 
piece  of  wood,  in  order  to  make  a  shape  something  like 
Fig.  164. 

This  cannot  well  be  made  with  solid  wood  on 
account  of  the  difficulty  of  guiding  a  rabbet  plane  along 


FIG.  164. 

the  obtuse  angle,  without  the  corner  of  the  iron  cut- 
ing  into  the  other  side.  The  best  way  of  overcoming 
this  difficulty  is  to  use  the  method  as  shown  at  Fig.  164. 
But  this  introduces  another  problem.  How  can  the 
feather-edge  be  glued  on  and  still  be  smooth,  without 
a  subsequent  planing?  Of  course  the  trouble  comes 
from  the  fact  that  a  thin  piece  of  wood  on  being  made 
wet  with  glue,  will,  unless  held  in  some  way,  warp  and 
curl  all  out  of  shape  while  drying.  A  way  of  over- 
coming this  difficulty  will  now  be  described.  After 
having  prepared  both  pieces  to  the  shape  indicated  in 
the  figure,  get  out  a  strip  of  wood  about  l/2  inch  by  T 
inch,  and  long  enough  to  extend  the  whole  length  of 

219 


220  WOOD  PATTERN-MAKING 

the  piece  to  be  glued ;  drive  a  number  of  brads  through 
it  about  6  inches  apart.  This  strip  must  exactly  fit  the 
whole  length.  Now  prepare  a  piece  or  pieces  of  good 
paper  about  il/2  or  2  inches  wide,  and  long  enough  to 
extend  the  whole  length.  Apply  the  glue  to  the  feather- 
edged  piece,  put  it  in  place,  and  tack  it  with  a  brad  or 
two  so  that  it  will  not  slip  around  out  of  place.  Then 
lay  the  paper  on  top  of  the  thin  feather-edge  of  the 
piece  being  glued  on,  and  on  this  lay  the  strip  of  wood 
so  that  one  edge  comes  exactly  along  and  even  with 
the  thin  edge ;  then  drive  the  brads  down,  which  will 
pull  down  the  thin  edge  into  place.  Examine  the 
feather-edge  to  see  that  it  is  down  tight  to  the  other 
piece.  If  any  spots  are  found  that  are  not  in  contact, 
put  in  another  nail  at  that  place.  The  paper  is  em- 
ployed in  this  case  to  prevent  the  strip  from  sticking 
to  the  work,  if  by  chance  some  glue  should  get  on  to 
the  upper  side  of  the  thin  edge.  Moreover,  if  the  edge 
is  very  thin,  the  glue  is  very  likely  to  ooze  through  the 
pores  of  the  wood  and  thus  glue  the  strip  to  the  work ; 
when  taken  off,  it  would  tear  up  some  of  the  wood  and 
make  it  rough.  By  interposing  the  paper,  this  is 
prevented. 

The  work  should  now  be  allowed  to  stand  for 
several  hours,  or  until  the  glue  is  thoroughly  dry.  If 
the  strip  be  then  removed,  it  will  be  found  that  the 
feather-edge  has  become  practically  one  with  the  other 
piece,  and  all  that  is  needed  to  finish  the  job  is  to  sand- 
paper the  surface. 


LARGE  LATHE  CHUCKS 

The  method  of  building  a  chuck  shown  at  Fig.  139, 
on  page  197  is  very  good  for  one  of  12  to  20  inches  in 
diameter;  but  larger  ones  should  be  built  as  illustrated 
by  Fig.  140  on  page  198.  Of  course  the  size  will  deter- 
mine the  number  of  arms  required ;  for  chucks  up  to 
four  feet  in  diameter,  four  arms  of  two  inches  by  six 
inches  in  cross  section  would  be  suitable ;  if  larger  than 
that,  it  would  be  preferable  to  use  more  arms,  so  that 
the  segmental  pieces  joining  the  arms  need  not  be  so 
long  or  wide.  In  building  all  these  chucks,  each  piece 
of  corresponding  shape  and  position  should  be  of  the 
same  size  and  weight  as  nearly  as  possible,  so  that  the 
chuck  will  be  accurately  balanced ;  otherwise,  it  will 
be  impossible  to  do  good  work,  and  besides,  an  extra 
strain  will  be  put  on  the  lathe,  which  may  cause  an 
accident.  If,  after  building  a  chuck,  it  is  found  to  be 
out  of  balance,  it  can  be  balanced  by  fastening  a  block 
of  wood  to  the  back  on  the  light  side. 


221 


LUGS  OR  PROJECTIONS  FOR 
MACHINISTS'  USE 

Some  castings  must  have  special  parts  cast  on 
them  which  serve  the  purpose  of  holding  them  in  a 
machine  while  they  are  being  worked  upon,  but  are 
usually  cut  off  after  the  machine  work  is  completed. 
It  is  the  pattern-maker's  business  to  provide  for  these 
parts  on  the  pattern.  One  form  of  such  a  casting  is 
a  piston-ring  shown  at  Fig.  165.  The  pattern  for  this 


FIG.  165. 


FIG.  166. 


should  be  made  large  enough  so  that  two  to  four  rings 
may  be  made  from  the  same  casting,  leaving  plenty 
of  stock  for  finish.  A  good  allowance  for  this  is  about 
l/4  inch  on  each  surface.  The  reason  for  this  extra 
allowance  is  that  these  rings,  being  comparatively 
small  in  cross  section,  the  metal  must  be  very  clean 
and  sound  to  give  the  required  strength.  As  the  sur- 
face of  castings  is  usually  more  or  less  porous,  it  is 
necessary  to  turn  off  this  outside  part  in  order  to  get 
down  to  the  more  solid  metal  on  the  inside.  The  pattern 
for  a  piston-ring  of  this  size  should  be  made  as  repre- 
sented by  Fig.  166.  The  projections,  c,  c,  c,  called  lugs, 

222 


MISCELLANEOUS  PATTERN  WORK 


223 


are  for  the  purpose  of  bolting  the  casting  to  the  lathe 
chuck  while  the  rings  are  being  turned.  This  is  the 
usual  form  in  which  piston-ring  castings  are  sent  to 
the  machine  shop  and  is  the  best  way  for  this  particular 
job.  If  these  lugs  are  not  provided,  the  machinist  has 
to  grip  the  casting  in  a  chuck ;  this  is  liable  to  spring 
it,  so  that  the  resulting  rings  will  not  be  true,  as  they 
must  be,  to  fit  the  cylinder. 


FIG.  167. 


Another  way  of  providing  for  the  convenience  of 
the  machinist  is  illustrated  by  Fig.  167.  Two  different 
methods  are  illustrated  here — one  being  on  the  outside 
of  the  casting,  the  other  on  the  inside.  This  casting 
is  the  column  for  a  small  drill  press.  It  is  finished  the 
whole  of  the  distance  A,  so  it  will  have  to  be  mounted 
in  the  lathe  between /centers.  In  order  that  this  may 
be  done,  there  will  have  to  be  a  boss  cast  on  at  C  and 
a  bar  cast  in  across  the  round  opening  at  B.  This  latter 
need  not  be  cut  out,  as  it  will  be  entirely  hid  and  out 


224  WOOD  PATTERN-MAKING 

of  the  way  in  the  completed  machine.  The  boss  at  C 
may  be  cut  off  or  allowed  to  remain  to  suit  the  fancy 
of  the  designer.  These  are  examples  of  simple  con- 
trivances to  accommodate  the  machinist. 


FINISHING  PATTERNS 

After  the  woodwork  of  the  pattern  is  completed  it 
must  be  "finished"  by  the  application  of  one  or  more 
coats  of  varnish,  all  small  holes  or  other  defects  in  the 
material  and  workmanship  filled  with  beeswax,  and 
the  whole  surface  made  smooth  so  that  it  will  draw 
easily. 

This  is  usually  done  in  the  following  manner:  The 
dust  from  sandpapering  is  all  cleaned  off  with  either 
brush  or  waste  and  then  a  coat  of  moderately  thick 
varnish  is  evenly  applied.  When  this  is  dry  all  nail- 
holes  and  any  defects  in  material  are  filled  with  bees- 
wax; if  any  wax  fillets  are  to  be  put  in  they  should 
also  be  done  at  this  stage.  As  this  first  coat  of  varnish 
drys  it  leaves  the  surface  of  the  wood  slightly  rough ; 
this  is  caused  by  the  wetting  and  drying  of  the  varnish 
which  raises  the  grain  of  the  wood.  This  may  now  be 
smoothed  down  by  sandpapering  it  with  fine  and  partly 
worn  sandpaper  until  it  becomes  smooth  to  the  touch. 
This  is  all  that  needs  to  be  done  if  the  pattern  is  to  be 
used  but  once  or  twice.  If  it  is  to  be  used  frequently 
one  or  two  more  coats  should  be  applied.  For  a  per- 
manent finish,  several  thin  coats  will  give  better  results 
than  one  or  two  thick  ones,  and  will  also  make  a  better 
appearance.  To  make  a  very  nice  finish  each  coat 
should  be  rubbed  smooth  with  fine  sandpaper  before 
applying  the  next.  When  patterns  become  rough  from 
use  in  the  foundry,  or  from  any  cause,  they  should  be 
cleaned  and  refinished,  for  if  a  pattern  is  smooth  and 
well  finished  it  will  give  the  molder  little  trouble  and 
hence  will  not  receive  such  hard  usage.  If  a  pattern 

225 


226  WOOD  PATTERN-MAKING 

is  rough  the  molder  must  rap  and  jar  it  considerably 
in  order  to  draw  it,  and  such  treatment  always  injures 
wood  patterns.  In  finishing  patterns  a  varnish  differ- 
ing in  color  from  that  used  for  the  body  of  the  pattern 
should  be  put  on  all  core-prints,  so  that  the  molder 
can  tell  at  once  the  general  position  the  cores  will 
occupy  in  the  mold. 


LOOSE  PIECES 

It  is  almost  impossible  to  make  some  patterns  with- 
out loose  pieces,  however  objectionable  they  may  be. 
They  are,  in  some  cases  at  least,  preferable  to  cores. 
When  a  choice  must  be  made  between  a  core  and  a 


FIG.  168. 


loose  piece  the  latter  should  generally  be  chosen,  as  it 
will  insure  a  truer  casting.  These  loose  pieces  are 
usually  held  in  place  on  the  pattern  during  the  process 
of  molding  by  skewers  or  draw-pins.  Brads  of  suit- 
able size  for  the  job  in  hand  and  bent  to  a  right  angle 
near  the  head  make  good  draw-pins.  For  standard 
patterns  it  is  better  to  fit  these  loose  pieces  to  the  pattern 

227 


228  WOOD  PATTERN-MAKING 

with  dovetails,  because  when  so  fitted  they  are  less 
liable  to  be  pushed  out  of  place  by  the  molder  in 
ramming  the  sand  around  them.  Another  reason  is 
that  the  moulder  does  not  have  to  stop  and  take  out 
any  skewers,  but  can  go  right  on  until  the  mold  'IL  all 
rammed  up.  In  fact  no  notice  need  be  taken  of  the  loose 
pieces  until  after  the  main  part  of  the  pattern  has  been 
pulled.  The  best  way  to  fit  these  dovetail  pieces  is  to 
bevel  them  on  the  edges,  and  also  in  their  thickness  as 
shown  in  Fig.  168.  They  should  be  fitted  very  accu- 
rately as,  if  they  are  not,  they  are  very  liable  to  stick 
when  drawing  the  pattern.  The  fact  that  they  are 
beveled  in  both  directions  as  suggested  above  and 
shown  in  the  cut  will  almost  always  insure  them  against 
sticking. 


STANDARD  PATTERNS 


Standard  patterns  made  of  wood,  and  often  used, 
should  be  made  as  durable  as  it  is  possible  to  make 
them,  using  hard  wood,  such  as  mahogany  or  cherry, 
for  all  the  parts  that  come  in  direct  contact  with  the 
sand.  For  all  parted  patterns,  metal  pattern  pins  should 
be  used,  brass  being  the  best.  The  first  cost  is  greater, 
but  time  and  labor  required  for  applying  them  is  less, 
and,  most  important  of  all,  they  never  stick,  if  properly 
fitted  at  first,  so  that  in  the  "long  run"  they  are  the 
cheapest;  and  standard  patterns  are  usually  made  for 
the  "long  run." 

Rapping  and  draw-plates  should  always  be  fitted 
to  all  standard  patterns,  as  they  will  save  their  cost  in 
repair  work  in  a  very  short  time,  to  say  nothing  about 
the  convenience  of  the  molder.  There  are  several 
kinds  of  these  plates  on  the  market  at  very  reasonable 
prices.  For  anything  except  very  large  patterns,  plates 
combining  both  rapping  and  drawing  holes  are  the  best. 
The  rapping  holes  in  these  plates-  are  simply  drilled ; 
drawing  or  lifting  holes  are  taped  to  fit  some  standard 
screw  thread.  Another  method  of  preparing  standard 
patterns  for  the  foundry  is  to  fit  them  to  a  follow-board. 
This  is  almost  always  done  when  a  large  number  of 
castings  are  wanted  from  a  pattern  that  requires  an 
irregular  parting,  or  if  the  pattern  is  thin  in  cross  section 
and  is  liable  to  be  injured  by  ramming  the  sand  around 
it.  The  cope  side  of  the  pattern  is  fitted  into  the 
top  side  of  the  board  down  to  where  the  molder  will 
make  his  parting,  and  the  board  cut  to  such  a  shape  as 

229 


230  WOOD  PATTERN-MAKING 

will  form  the  parting.  This  follow  board  with  its  pat- 
tern laid  in  place,  is  used  the  same  as  a  turn  over  or 
molding  board  in  molding  a  simple  pattern. 


STOVE  PATTERN-MAKING 

The  fundamental  ideas  underlying  the  making  of 
patterns  for  stove  castings  are  practically  the  same  as 
for  machinery  pattern-making;  but  on  account  of  the 
shape  and  generally  delicate  character  of  the  castings 
required,  the  methods  of  their  production  are  in  many 
respects  quite  different.  The  drawings  furnished  the 
stove  pattern-maker  are  also  radically  different  from 
those  sent  to  the  maker  of  machinery  patterns.  Gener- 
ally a  new  design  of  a  stove  is  first  developed  by  making 
a  drawing,  and,  at  the  same  time,  a  model  is  also  worked 
out  in  wax  or  clay,  and  in  some  cases  a  complete  model 
is  made  of  wood. 

This  gives  the  designer  the  opportunity  of  compar- 
ing curves  and  other  ornamental  features'of  the  finished 
stove  which  is  impossible  from  drawings  alone,  and 
enables  him  to  see  how  it  will.be  best  to  have  the  dif- 
ferent parts  fit  each  other  at  the  many  joints  necessary. 
This  is  especially  advantageous  in  the  case  of  artistic 
heating  stoves,  on  which  there  is  usually  a  large  amount 
of  carving.  A  model,  however,  is  not  generally  made 
in  the  case  of  plain  work,  such  as  cook  stoves  or  ranges, 
these  being  carried  through  from  drawings  alone. 
There  are  also  several  tools  that  are  used  by  the  stove 
pattern-maker  that  are  not  used  by  others.  These  are 
made  necessary  by  the  requirements  of  the  art;  one  of 
which  is  that  the  castings,  and  therefore  the  patterns, 
must  generally  be  of  uniform  thickness,  and  compara- 
tively thin  in  cross  section,  usually  not  exceeding  i-io 
inch. 

Almost   all    machinery  pattern   drawings   are   made 

231 


232  WOOD  PATTERN-MAKING 

and  all  dimensions  given  in  finished  sizes  so  they  may 
be  used  in  the  machine  shop  as  well  as  in  the  pattern 
shop.  Stove  pattern  drawings  seldom  go  farther  than 
the  pattern  shop.  They  are  usually  made  full  size  and 
in  some  cases  at  least,  the  dimensions  are  not  marked 
on  them,  so  that  the  pattern-maker  must  take  the  sizes 
directly  from  the  drawing  by  measuring  it,  and  this  is 
usually  done  with  trams  and  applied  to  the  shrink  rule 
to  be  used.  The  plan  is  first  drawn  and  then  the  eleva- 
tions or  side  views  are  drawn  in — usually  on  the  same 
paper,  so  that  the  lines  of  each  view  are  all  mixed  up, 
which  makes  the  reading  of  them  very  difficult  for  those 
unfamiliar  with  this  kind  of  work.  Sometimes  the  lines 
of  these  different  views  are  made  with  different  colors, 
so  as  to  be  more  easily  read.  The  same  shrink  rule 
to  be  used  in  making  the  original  patterns  is  used  by 
the  draftsman  in  making  these  drawings. 

The  stove  wood  pattern-maker  is  provided  with 
from  five  to  seven  different  shrink  rules ;  the  one  to  be 
used  for  any  given  pattern  is  determined  by  the  kind  of 
metal  of  which  the  master  pattern  is  to  be  made  and 
also  the  method  of  producing  it.  These  rules  are  spoken 
of  as  one  shrink,  two  shrink,  or  one  and  a  half  shrink 
according  to  the  ratio  of  the  rule  to  the  standard  rule, 
the  word  "shrink"  in  this  instance  meaning  the  general 
amount  allowed  in  making  machinery  patterns,  viz :  ^ 
inch.  Which  one  of  these  is  to  be  used  is  determined 
by  the  material  to  be  used  in  the  production  of  the 
master  pattern. 

Because  of  the  necessity  of  beveling  the  edges  of 
all  stove  plates  where  they  come  together,  and  to  have 
these  bevels  uniform  throughout  the  stove,  it  has  been 


MISCELLANEOUS  PATTERN  WORK  233 

found  advantageous  by  stove  pattern-makers  to  have 
a  set  of  "bevel  gages"  for  measuring  and  laying  out 
these  bevels.  Such  a  set  of  bevel  gages  was  originated 
by  Mr.  N.  Vedder,  formerly  a  stove  designer  of  Troy, 
N.  Y.  These  have  come  into  extensive  use  among  stove 
manufacturers  during  the  last  few  years.  In  order  that 
these  gages  may  be  convenient  for  use,  they  are  made 
of  thin  wood  or  metal  similar  to  the  triangles  used  in 
making  mechanical  drawings.  There  are  eight  of  these 
bevels  in  use  ranging  from  one  of  about  2°  to  that  of  30°, 
which  is  the  largest  angle  used.  These  are  numbered  as 
follows :  From  two  degrees  to  eight  degrees  are  four 
bevels  numbered  by  ciphers,  two  degrees  being  desig- 
nated by  oooo,  the  next  by  ooo,  the  next  by  oo,  and  the 
next  by  o,  which  is  eight  degrees.  The  other  four  bevels 
are  designated  by  the  numerals  i,  2,  3,  4,  number  one  be- 
ing an  angle  of  10°,  number  two,  16-2/3°,  number  three, 
231/3°,  and  number  four,  30°.  As  in  a  large  part  of  stove 
patterns  it  is  necessary  to  make  them  of  curved  out- 
line, and  as  these  curves  cannot  very  well  be  marked 
out  with  trams,  a  set  of  standard  curves  have  been 
adopted.  These  are  used  by  having  them  made  up  of 
thin  wood  or  metal  (metal  being  best)  so  they  may  be 
used  in  the  same  way  as  the  bevel  gages.  These  are 
likewise  used  by  both  draftsman  and  pattern-maker. 

It  sometimes  becomes  necessary  to  make  a  center 
line  across  a  carved  or  other  uneven  surface.  For  this 
purpose  a  simple  contrivance  known  as  a  "vertical 
plumb"  has  been  devised.  It  consists  of  two  boards 
fastened  together  lengthwise  at  their  edges  and  at  right 
angles  to  each  other.  This  must  be  set  up  on  two  par- 
allel blocks  of  such  a  height  as  will  raise  it  above  a  pat- 


234  WOOD  PATTERN-MAKING 

tern  or  other  object  on  which  it  is  required  to  make  a 
straight  line  across  the  uneven  surface.  A  scriber  with 
which  to  make  the  mark  is  also  needed.  This  consists 
of  a  thin  flat  piece  of  wood  on  which  is  fastened  a  thin 
plate  of  steel  sharpened  to  a  keen  cutting  edge. 

Stove  patterns  must  be  carved  very  thin  and  made 
of  uniform  thickness  throughout.  If  they  are  not  the 
castings  will  not  be  of  even  thickness,  so  that  one  part 
will  cool  more  rapidly  than  others,  thereby  causing  them 
to  warp  and  sometimes  to  crack  from  the  shrinkage 
strains.  To  insure  that  the  patterns  are  of  uniform 
thickness,  a  special  form  of  calipers  is  used  for  meas- 
uring their  thickness.  These  calipers  are  made  with  a 
loose  joint  something  like  a  pair  of  shears.  Just  at  the 
back  of  these  shear-like  handles  are  short  projections, 
through  one  of  which  a  screw  is  put,  the  end  of  the 
screw  abutting  against  the  other.  The  points  of  the 
calipers  may  be  set  to  a  definite  distance  apart,  the  above 
screw  turned  in  until  its  end  comes  in  contact  with  the 
other  projection  mentioned.  The  calipers  may  now  be 
opened  and  passed  over  any  intervening  thick  part  of  a 
pattern  and  the  points  closed  again  to  the  same  distance 
as  before.  Now  if  the  screw  does  not  touch,  or  come  to 
a  bearing,  the  pattern  is  too  thick  at  that  point  and  must 
be  pared  down.  Most  stove  plate  work  is  very  uneven 
on  the  surface  on  account  of  the  carving  and  other  orna- 
mental work.  In  order  that  the  pattern  may  be  of  equal 
thickness  it  has  to  be  "backed  out,"  as  it  is  called,  that 
is,  it  has  to  be  carved  out  on  the  back  to  conform  to  the 
shape  of  the  carving  on  the  front.  This  makes  it  neces- 
sary that  the  outlines  of  the  carving  be  transferred  to 
the  back.  This  is  most  easily  and  accurately  done  by 


MISCELLANEOUS  PATTERN  WORK  235 

the  use  of  what  are  known  as  marking  calipers.  These 
are  usjually  made  of  hard  wood  and  similar  in  shape  to 
the  ordinary  wing  caliper,  that  is,  hinged  together  at  the 
end  of  what  may  be  called  the  handle.  One  leg  is  pro- 
vided with  a  steel  point,  the  other  with  a  pencil  point. 
A  spring  is  set  in  between  the  two  parts  of  the  handle 
that  tends  to  open  the  points,  so  that  in  order  to  bring 
the  points  together  this  spring  must  be  compressed.  By 
following  the  outline  of  the  carving  with  the  steel  point, 
and  at  the  same  time  compressing  the  spring  and  keep- 
ing the  pencil  point  in  contact  with  the  back  of  the 
pattern,  the  outline  may  be  accurately  and  rapidly  trans- 
ferred to  that  side.  Many  parts  of  stove  patterns  have 
to  be  joined  on  an  angle,  and  as  the  stock  is  generally 
very  thin,  it  is  quite  difficult  to  joint  the  edges  to  the 
correct  angles ;  therefore  it  is  necessary  that  some  device 
be  provided  for  holding  the  stock  in  a  fixed  position  with 
regard  to  the  plane.  For  this  purpose  some  form  of 
shoot-board  is  found  useful.  One  form  of  shoot-board 
is  represented  by  Fig.  125  on  page  166.  For  stove  pat- 
tern work,  however,  it  must  be  more  complicated  than 
is  this,  as  it  is  necessary  that  it  be  adjustable  to  several 
different  angles,  and  be  set  accurately  to  any  given 
angle  within  its  limits.  As  a  large  amount  of  carving 
is  necessary  in  stove  pattern-making  which  cannot  be 
done  with  the  chisels  and  gouges  of  the  ordinary  pat- 
tern-maker's outfit,  the  stove  pattern-maker  is  provided 
with  a  series  of  carving  tools,  usually  about  twenty  in 
number.  In  large  establishments  making  stove  pat- 
terns, the  carving  is  usually  done  by  men  especially 
skilled  in  that  work,  and  in  some  cases  stove  patterns 
pass  through  the  hands  of  several  men,  each  doing  his 


236  WOOD  PATTERN-MAKING 

own  special  kind  of  work.  A  large  quantity  of  very 
thin  stock,  some  of  which  is  less  than  1/12  inch  in-thick- 
ness  is  required  for  this  class  of  patterns.  As  this 
cannot  very  well  be  made  on  the  ordinary  planer  with- 
out some  special  attachment,  a  suitable  one  is  provided 
for  the  planer  in  stove  pattern  shops  with  which  thin 
boards  may  be  planed  smoothly  and  to  a  uniform 
.thickness. 

Almost  all  machinery  patterns  are  fairly  thick  and 
stiff  enough  of  themselves  for  the  purpose  of  molding ; 
moreover,  in  the  production  of  this  class  of  patterns, 
the  application  of  the  principles  of  joinery  is  an  impor- 
tant part.  Stove  patterns  are  usually  very  thin,  and 
practically  of  uniform  thickness  throughout  and  there- 
fore require  special  treatment.  Stove  patterns  are 
rarely  stiff  enough  of  themselves  for  the  purposes  of 
molding  and. must  be  supported  by  what  is  called  a 
"match"  during  the  process  of  molding  to  produce  the 
metal  patterns.  The  match  is  very  frequently  made 
first  and  the  pattern  made  or  built  on  it.  In  many  cases 
these  patterns  are  very  intricate  having  quite  a  large 
amount  of  carving  on  them. 

Because  of  these  many  facts,  stove  pattern-making 
differs  considerably  from  ordinary  pattern-making  and 
is  a  distinct  branch  of  the  art.  The  original  pattern 
for  stove  work  is  usually  made  of  wood ;  in  some  shops, 
however,  original  patterns  are  sometimes  modeled  in 
clay  or  plaster-of-Paris.  From  this  original  pattern  a 
master  pattern  is  made  of  iron.  For  this  purpose,  how- 
ever, some  foundries  use  a  white  metal  alloy  consisting 
of  nine  parts  lead  and  one  part  antimony,  which  has  a 
shrinkage  of  1/16  inch  per  foot.  This  is  preserved  and 


MISCELLANEOUS  PATTERN  WORK  237 

from  this  the  pattern  to  be  used  in  the  production  of 
the  castings  for  the  stoves  is  made.  The  original  wood 
patterns  are  rarely  kept  as  they  are  sure  to  change  their 
form. 

There  are  several  distinct  processes  used  in  making 
stove-patterns,  but  on  account  of  space  they  cannot  be 
described  and  will  for  that  reason  be  just  barely  men- 
tioned. One  of  these  is  what  is  known  as  the  "carving 
and  backing-out  wooden  patterns."  This  is  the 
simplest,  and  means  that  the  pattern  is  carved  out  of 
wood  to  the  exact  shape  and  thickness.  For  a  small 
pattern  like  a  stove  leg  for  instance,  this  would  be  all 
that  is  necessary  from  which  to  make  the  mold  for  the 
master  pattern.  For  large  patterns  in  this  process,  how- 
ever, a  match  or  follow-board  must  be  made  to  support 
the  pattern  while  ramming  up  the  nowel.  Another  dis- 
tinct process  is  the  "wax  process."  This  is  used  to 
avoid  backing-out  the  wooden  pattern.  Considerable 
practice  or  experience  is  necessary  to  work  this  method 
successfully.  Then  there  is  the  "carving  and  blocking" 
process,  in  which  the  molder  surrounds  the  pattern 
with  a  thin  layer  of  blocking  just  the  thickness  of  the 
required  casting,  when  ramming  up  the  drag.  In  all 
these  processes  the  block  of  wood  used  for  the  pattern 
is  "built  up"  of  thin  pieces  of  wood,  so  as  to  reduce  the 
effects  of  shrinking  and  swelling  to  the  minimum.  In 
many  stove  patterns  allowance  has  to  be  made  for  the 
warping  of  the  casting.  This  is  usually  done  by  pre- 
paring a  special  form  of  mold-board  which  is  curved  so 
as  to  give  the  required  curve  to  the  pattern,  as  it  is  built 
on  to  and  over  the  mold-board.  This  is  necessary  be- 
cause a  casting  made  from  a  straight  pattern  often 


238  WOOD  PATTERN-MAKING 

comes  out  warped  or  bent  and  it  becomes  necessary  to 
bend  the  pattern  in  the  opposite  direction  so  that  the 
casting  will  come  out  straight. 

In  machinery  or  general  pattern-making  the  term 
"master  pattern"  is  used  in  speaking  of  the  original 
wood  pattern  when  a  metal  pattern  is  to  be  made,  from 
which  to  make  the  castings  wanted.  It  is  not  so  used, 
however,  in  connection  with  stove  pattern  making. 
The  use  of  the  term  in  this  division  of  the  art  means 
the  metal  pattern  that  is  made  from  the  original  wood 
pattern,  from  which  the  regular  patterns  are  made  that 
are  used  in  the  foundry  for  making  the  stove  castings. 
These  master  patterns  are  very  costly  to  make  and 
therefore  are  very  valuable,  and  are  very  carefully 
stored.  A  set  of  these  patterns  for  an  ornate  heating 
stove  frequently  costs  from  fifteen  hundred  to  two 
thousand  dollars. 


INDEX. 


Angle  of  cutting  wedge...  41 

Annular  patterns   132,  163 

Architectural  patterns   ....  90 

Arms  of  wheels  195,  201 

Assembly  ing  pulley 176 

Backing  out  stove  patterns  234 

Beeswax     98 

Bench    9 

Bevel  gages 233 

Bevel  gear  patterns 196 

Bit,  auger    27 

brace   29 

center    28 

countersink    29 

drill    27 

square  hole   27 

Black  varnish  97 

Block-plane  37 

Board  foot    12 

Boxing  up  patterns 129 

Brads    98 

Brass  for  patterns 94 

shrinkage  of 88 

Cabinet  turning 60 

Calculating  data  for  a  cast 

gear   191 

Calipers  for  stove  pattern- 
making   234 

inside    70 

marking    235 

outside    .  .70 


Carpenter's  plow  39 

Car  wheel,  double  flange..  118 

single  flange   117 

Castings,  estimating  weight 

of   209 

Chisels    19 

Chords  of  curves.. 164 

Chuck,  cup    62 

fork   61 

large    221 

screw  61 

Clamp   32 

Combining  pieces  of  wood 

in  patterns 94 

Concentric  176 

hubs  to  be 177 

layers    47 

Constructional  joints 125 

Copal  varnish 98 

Cope  77,  78 

bars   79 

Core  board   216 

Core-box    108 

conical     144 

ends  146 

plane    40 

plane,   use   of 143 

Core-prints 108 

Cores     107 

Core    strickle    216 

Corners  in  patterns 101 

inside     101 

outside    .                          . .  101 


239 


240 


WOOD  PATTERN-MAKING 


INDEX— (Continued). 


Counter  ribs  127 

Curvature  of  plane-irons..  37 

Cutting  edge,  whetting  of.  43 

Cylindrical  core  prints.  110,  112 

summary  of   115 

Dividers  16 

laying  out  angles  with. . .  16 

Double  shrinkage  pattern . .  94 

Draft  on  patterns  85 

Drawings,  reading  of 53 

Emery  wheels  for  grinding 

tools    42 

Engineer,  requirements  of.  75 

Face-plate  197,  198 

Faces,  working 136 

Felling  trees  48 

Filing  saws  •. 26 

Fillets   101 

applying  leather 105 

applying  wax   106 

materials  for   103 

size  of -. . .  102 

to  strengthen  castings . . .  102 

wood  103 

Gage  marking  17 

mortice  18 

Gear  patterns,  arms  for...  195 

teeth  for  187,  188 

tooth  blocks  for 187 

Gears  183 

bevel  196 

laying  out  of 184,  185 

patterns  for  183 


Gears 

tooth  curves  for 191 

Glue  95 

Glue,  to  resist  moisture...  96 

use  of  95 

Gluing  feather  edge  board.  219 

Gluing  up  work 96 

Gouges  20 

turning  63 

Grain  of  wood  47 

Grinding  chisel  42 

cutting  wedges 41 

plane-iron    41 


Handsaw    

Handscrew    

.use  of  

Heart  wood  . . 


Irregular  parting 119 

Jointer  plane    33 

Joints,     constructional     in 

patterns    125 

molder's   in  patterns 116 

Keyhole  saw  23 

Knife,  draw    21 

Lagging    131 

Lagging  up  131 

Lags,  patterns  made  of. ...  131 

Laying  out  gear  teeth 193 

Laying  out  pulley  arms. . . .  173 

Leather  fillets 105 

Legal    standard     (unit    of 

measure)    11 

Loam  patterns   215 


WOOD  PATTERN-MAKING 


241 


INDEX— (Continued). 


Lugs  for  machinists'  use..  222 

Lumber,   quarter-sawn.  .46,  92 

Mahogany    93 

Marking  calipers  235 

Master  patterns  . .  .94,  236,  238 

Match   236 

Measuring  appliances    ....  11 

Medullary  ray  46,  51,  92 

Metals,  shrinkage  of 87 

Miter-box    30 

Molding   77 

Mortise  gage    18 


Nails   

Nowel    

Oilstone    

Open  joints   .... 


98 

78,    79 

43 

128,  129 


Parting,    molders' 116 

pattern-makers'    116 

Pattern  lathe   60 

Pattern-making  and  mold- 
ing, (connection  be- 
tween)    74 

Pattern  pins   148 

Patterns,  wood  for 91,    93 

Pins,  pattern 148 

Plane,  block   37 

core  box    40 

dado    39 

jack    33,    37 

jointer 33 

plow    39 

rabbet   38 

smoothing    33 


Planes,  combination  39 

use  of  34 

with  narrow  mouth 35 

wood  36 

Plane-iron  35 

curvature  of  37 

Pulley,  pattern  for 163 

Quarter-sawn  lumber  .  .46,  92 

Sandpaper   95 

Sap    47 

side  of  board 92 

Saw,  back   22 

compass    23 

filing    25 

hand 22 

kerf   25 

keyhole  23 

setting 25 

Sawing  out  pulley  rim....  175 

Sawing  segments  ' 164 

Scale  on  castings 90 

Scales  for  measuring 11 

Scraping  a  surface  67 

tools    63,  64 

Screwdriver    30 

Screws    99 

in  end  wood 99 

Sharpening  lathe  tools 69 

Shellac  varnish    97 

Shoot  board   166 

Snrink  rule   11,  88 

Shrink  rules  for  stove  pat- 
tern-makers    232 

Shrinkage,  double 94 

of  aluminum  . .  .88 


242 


WOOD  PATTERN-MAKING 


INDEX— (Continued). 


Shrinkage  of 

Turning 

brass    

88 

in   cup   chuck  

62 

iron    

88 

lathe    

60 

steel  

88 

pattern    

60 

wood    49, 

51 

pulley  rim   

170 

Skeleton   patterns 

215 

tools                              .63 

65 

Skewering  on  loose  pieces. 

121 

Square,    combination  

15 

Varnish,  black   

97 

framing    

13 

copal    

98 

try    

14 

red  

98 

Stock  for  stove  patterns.  . 

236 

shellac  

97 

Stop-off  pieces  . 

127 

yellow 

97 

Stove   pattern-making  

231 

Vertical  plumb  

233 

Strickles  

216 

sides  pattern  

84 

Surfacing  planes   

33 

iVise,    pattern-makers'  

9 

Swelling  of  wood  50, 

51 

Warp,  allowance  for  

90 

Taper  on  patterns    

85 

Warping  in  castings   ...91, 

237 

T-bevel  

16 

of  wood  51, 

91 

Thin  boards,  building  of.  . 

126 

Waxing  iron  patterns   .... 

98 

disks,  building  of  

126 

Winding  sticks  

33 

Trimmer      (also      frontis- 

Wood drills    

27 

piece)    

166 

fillets,  forming  of  

103 

Turning,  cabinet   

60 

for  patterns  91, 

93 

chisel     

63 

Wood    patterns,    definition 

use  of 

66 

of 

72 

gouge    

63 

Working  sketches  

138 

use  of  .  . 

65 

Worm  wheel  .  . 

119 

Books  on  the  Manual  Arts 


HANDWORK  IN  WOOD. 

By  WILLIAM  NOYES. 

A  handbook  for  teachers  and  a  textbook  for  normal 
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ing and  measuring,  hand  tools,  wood  fastenings,  equipment 
and  care  of  the  shop,  the  common  joints,  types  of  wood 
structures,  principles  of  joinery,  and  wood  finishing.  304 
illustrations — excellent  pen  drawings  by  Anna  Gausmann 
Noyes.  Price,  $2.00. 

ESSENTIALS  OF  WOODWORKING. 

By  IRA  S.  GRIFFITH. 

A  textbook  written  especially  for  the  use  of  grammar 
and  high  school  students.  A  clear  and  comprehensive 
treatment  of  woodworking  tools,  materials,  and  processes, 
to  supplement,  but  not  to  take  the  place  of  the  instruction 
given  by  the  teacher.  The  book  does  not  contain  a  course 
of  models ;  it  may  be  used  with  any  course.  It  is  illus- 
trated with  photographs  and  numerous  pen  drawings  by 
Edwin  V.  Lawrence.  Price,  $1.00. 

BEGINNING  WOODWORK.     At  Home  and  in  School. 

By  CLINTON  S.  VANDEUSEN. 

A  full  and  clear  description  in  detail  of  the  fundamental 
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tion is  given  through  directions  for  making  a  few  simple, 
useful  articles,  suitable  either  for  school  or  home  problems. 
The  book  contains  more  than  one  hundred  original  sketches 
and  ten  working  drawings  by  Edwin  V.  Lawrence.  Price, 
$1.00. 

WOODWORK  FOR  SCHOOLS  ON  SCIENTIFIC  LINES. 

By  JAMES  THOMAS  BAILEY  and  S.  POLLITT. 
The    American    edition    of   an    English   book   containing 
120  practical  problems,  many  of  which  have  been  designed 
to  correlate  mathematics  and  physical  science  with  manual 
training.     Price,  75  cents. 


PUBLISHED  BY 

The    Manual    Arts    Press,     Peoria,    Illinois 


Books  on  the  Manual  Arts 


PROBLEMS  IN  WOODWORKING. 

By  M.  W.  MURRAY. 

A  convenient  collection  of  good  problems  consisting  of 
forty  plates  bound  in  heavy  paper  covers  with  brass 
fasteners.  Each  plate  is  a  working  drawing,  or  problem 
in  benchwork  that  has  been  successfully  worked  out  by 
boys  in  one  of  the  grades  from  seven  to  nine  inclusive. 
Price,  75  cents.  Board  covers,  20  cents  extra. 

PROBLEMS  IN  FURNITURE  MAKING. 

By  FRED  D.  CRAWS  HAW. 

This  book  consists  of  32  plates  of  working  drawings 
suitable  for  use  in  grammar  and  high  schools  and  24  pages 
of  text,  including  chapters  on  design,  construction  and 
finishes,  and  notes -on  the  problems.  Price,  $1.00.  Board 
covers,  20  cents  extra. 

PROBLEMS  IN  WOOD-TURNING. 

By  FRED  D.  CRAWSHAW. 

In  the  first  place  this  is  a  book  of  problems— 25  plates 
covering  spindle,  face-plate,  and  chuck  turning.  In  the 
second  place  it  is  a  textbook  on  the  science  and  art  of 
wood-turning  illustrated  by  fifty  pen  sketches.  It  gives, 
the  mathematical  basis  for  the  cuts  used  in  turning.  In 
the  third  place  it  is  a  helpful  discussion  of  the  principles 
of  design  as  applied  to  objects  turned  in  wood.  It  is  a 
clear,  practical  and  suggestive  book  on  wood-turning. 
Price,  80  cents.  Board  covers,  20  cents  extra. 

PROBLEMS  IN  MECHANICAL  DRAWING. 

By   CHARLES    A.    BENNETT.     With    drawings   by   FRED 

D.  CRAWSHAW. 

This  book  consists  of  80  plates  and  a  few  explanatory 
notes,  and  is  bound  in  heavy  paper  covers  with  brass 
fasteners.  Its  purpose  is  to  furnish  teachers  of  classes 
beginning  mechanical  drawing  with  a  large  number  of 
simple,  practical  problems.  These  have  been  selected  with 
reference  to  the  formation  of  good  habits  in  technique,  the 
interest  of  the  pupils,  and  the  subjects  generally  included 
in  a  grammar  and  first-year  high  school  course.  Each 
problem  given  is  unsolved  and  therefore  in  proper  form  to 
hand  to  the  pupil  for  solution.  Price,  $1.00.  Board  covers, 
20  cents  extra. 


PUBLISHED  BY 

The    Manual    Arts    Press,     Peoria,    Illinois 


Books  on  the  Manual  Arts 


SELECTED  SHOP  PROBLEMS. 

By  GKORGE  A.  SEATON. 

A  collection  of  sixteen  problems  in  woodworking  made 
to  meet  the  needs  of  busy  teachers  of  manual  training. 
Each  problem  has  been  put  to  the  test  and  has  proven 
satisfactory  to  the  teacher  who  designed  it  and  the  pupil 
who  made  it.  Price,  20  cents. 

COPING  SAW  WORK. 

By  BEN.  W.  JOHNSON. 

Contains  working  drawings  and  suggestions  for  teach- 
ing a  course  of  work  in  thin  wood  that  is  full  of  fun  for 
the  children,  and  affords  ample  means  for  training  in 
form  study,  construction,  invention  and  careful  work. 
Has  been  called  ''applied  mechanics  for  the  fourth  grade." 
Price,  20  cents. 

THE  CONSTRUCTION  AND  FLYING  OF  KITES. 

By  CHARLES  M.  MILLER. 

This  contains  seven  .full-page  plates  of  drawings  of  kites 
and  fifteen  figures — over  forty  kites  shown.  Details  of 
construction  given;  a  kite  tournament  is  described.  Full 
of  interesting  suggestions.  Price,  20  cents. 

CLAY  WORK. 

By  KATHERINE  MORRIS  LESTER. 

This  book  has  been  written  by  a  grade  teacher  and  art 
worker  to  help  teachers  in  acquiring  the  technique  of  clay 
working,  and  to  give  them  suggestions  concerning  the 
teaching  of  the  several  types  of  clay  work  suited  to  pupils 
in  the  elementary  schools.  It  covers  the  study  of  natural 
forms,  the  human  figure  in  relief,  and  the  round,  animal 
forms,  story  illustration,  architectural  ornament,  tiles,  hand- 
built  pottery,  and  pottery  decoration.  The  book  is  richly 
illustrated  with  more  than  fifty  half-tone  and  line  cuts 
showing  processes,  designs,  and  the  work  of  children  from 
ten  to  twelve  years  of  age.  Price,  $1.00. 

THE  WASH  METHOD  OF  HANDLING  WATER  COLOUR. 

By  FRANK  FORREST  FREDERICK. 

A  brief,  clear,  comprehensive  text  printed  in  sepia-  and 
illustrated  with  wash  drawings  and  a  water-color  painting 
by  the  author.  Price,  50  cents. 

PUBLISHED  BY 

The    Manual    Arts    Press,     Peoria,    Illinois 


Books  on  the  Manual  Arts 


HANDWORK  INSTRUCTION  FOR  BOYS. 

By  DR.  ALWIN   PABST.     Translated  from  the  German 

by  BERTHA  REED  COFFMAN. 

This  is  a  notable  discussion  of  the  educational  value  of 
handwork,  by  the  director  of  the  school  for  training 
teachers  of  handwork  at  Leipsic.  It  traces  instruction  in 
handwork  thru  the  history  of  education,  points  out  its  place- 
in  the  several  types  of  schools,  and  gives  a  rapid  survey  of 
modern  systems  of  handwork  in  the  leading  civilized 
countries  of  the  world.  Price,  $1.00. 

HANDICRAFT  FOR  GIRLS. 

By  IDABELLE  MCGLAUFLIN. 

A  handbook  for  teachers,  detailing  a  five-years  course  in 
sewing  for  girls,  in  the  public  schools.  Chapters  on 
stitches,  fibers  and  fabrics,  cloth  and  cardboard  construc- 
tion, basketry,  dress  in  its  relation  to  art,  and  home  furnish- 
ing. It  is  definite  enough  to  be  thoroly  practical  and 
elastic  enough  to  suit  the  varied  conditions  in  rural,  village 
•  or  city  schools.  Price,  $1.00. 

SIMPLIFIED  MECHANICAL  PERSPECTIVE. 

By  FRANK  FORREST  FREDERICK. 

A  book  of  simple  problems  covering  the  essentials  of 
mechanical  perspective.  It  is  planned  for  pupils  of  high 
school  age  who  have  already  received  some  elementary 
training  in  mechanical  drawing.  It  is  simple,  direct  and 
practical.  Price,  75  cents. 

CLASSROOM  PRACTICE  IN  DESIGN. 

By  JAMES  PARTON  HANEY. 

A  concise,  up-to-date,  richly  illustrated  brochure  on  the 
teaching  of  applied  design.  Price,  50  cents. 

MANUAL  TRAINING  MAGAZINE. 

CHARLES   A.   BENNETT,  Editor;   WILLIAM   T.   B.UVDEX, 

Managing  Editor. 

Assisted  by  a  staff  of  associate  and  department  editors. 
Illustrated;  published  bi-monthly.  Subscription  price,  $1.50 
a  year. 


PUBLISHED  BY 

The    Manual    Arts    Press,     Peoria,    Illinois 


A     000  037  567     5 


